I dropped out.  Or maybe failed out - it wasn't a reasoned choice, I just couldn't make myself do it.  It was long enough ago that the world is different, and you and I are different, so don't take this too seriously, but I estimate it slowed me down by about a decade in getting really good at software engineering.

I think you're over-generalizing quite a bit.  The probabilities of future trajectory are very lumpy, and "optionality" doesn't mean much without specifying the options you're talking about.   More importantly, you're using far-mode arguments (general, long-term, non-specific) for pro and near-mode (specific scenarios that you have to actually do) for contra, which is going to be a painful awakening when you have to actually act.

If you actually have that better thing lined up, I think it's a pretty straightforward decision.  If you don't, it's a lot tougher to predict whether it exists.  The standard advice (which is easy to give and hard to take) is "do both".  Absolutely you should pass the classes you're in now.  Simply no question.  And see how far you get at lining up the specific thing you'd do if you didn't re-enroll.  You may find you can do a lot during school.  You may find that you WANT to drop out to do this other thing.  You may find that the other thing doesn't exist (or can't be found).

What you DON'T want to do is cross a random bridge, burn it to avoid retreat, and then find out that it was the wrong bridge.

As someone who evaluates and mentors young software engineers as part of his living and has for about thirty years now, "dropped out of UIUC to found an interesting startup" would strike me as being good a resume' on average as "fresh CS grad from UIUC".  What I would be worried about is the variance. I would grill very hard during the interview cycle, and skip no steps. The upside of the first candidate is at least as high as the second (probably higher), but the downside risks (e.g, that they are just a bullshit artist or a prima donna) are higher. Hiring young software engineers is very much a matter of expected value calculations ("moneyball", in the trade), and negative-EV engineers are very real possibilities.

That said, I very much wish you well. I've counseled three young engineers in my career to go pro without finishing college. None of them took the advice, but I'm pretty sure two of them would have had better outcomes if they did. In my experience, UIUC is a uniquely horrible environment, so much so that flight from there should always be a consideration. 

My two cents as someone who burned out with a full depressive episode in their junior year of an electrical engineering degree and managed to limp all the way to graduation:

• Don't underestimate the magnitude of what can go wrong in your head.  I've got some genetic factors and some childhood stuff that likely contributed, but anxiety and depression can and will cripple you for years if you let them.
• Get a blood test at your earliest convenience; make sure that you're not low on vitamin B12 or D, or have anything else obviously wrong.  I've heard enough stories about things like this (and had deficiencies myself) that indicate this is high-value.  It's also not hard to do or expensive (just ask your family doctor or the University Health Center; make sure to specify that you're curious about those deficiencies in particular).
• Don't fall for false dichotomies.  You're clearly smart enough to get creative.
  • One suggestion I've seen in this thread is taking a semester/year off to go work, which your University should be fine with.
  • Another suggestion, if you believe there is inherent value in a degree, is to Goodhart the degree itself.  Read this - you can consciously engage in half-assing your degree with everything you've got.  In other words, diplomas don't include grades.  In other other words, Cs get degrees.  Feel free to put in the absolute minimum that has you passing, take the easiest electives, etc., and spend the time you get back on other things.
  • Once you've had your first job, no one cares where you got your degree from.  Spending 55k per year is absurd - transfer to a cheaper college, or take a look at your local community college.  Most community colleges will have an agreement with four-year colleges for credits to transfer.  Drop out and enroll there, get the freshman/sophomore/core credits over with, then transition to a cheaper/online college for the degree.  You can also take this slowly - one community college class a semester can be done simultaneously with a full-time job, if you're so inclined, and most four-year colleges will have something for people with jobs.
• Reframe the question: if you've got three years left, each costing 55k, then would you willingly take 165k right now to walk away?  Would that 165k be worth more to you than an additional three years of education at college?
• I honestly don't believe that student loan debt is ever worth it, especially not for programmers.  Doctors maybe, but that's about it.  Whatever you do, plan out how you're going to wind up debt-free at the end.  Scholarships are great.  So is working.  Debt isn't.
• Isn't MIT's entire curriculum online?  Is there anything you can realistically gain from your current university that you can't get yourself in other ways?  Is the alumni network super valuable?  Is there an incubator you could take advantage of?

And a couple of general decision-helpers I like to use:

• It's twenty years later, and you're looking back on your life.  What will you regret not having done more, finishing your degree or striking out on your own?
• Take out a fair coin.  Heads you get the degree, tails you walk away.  Flip the coin, and pay attention to how you feel.  Are you hoping for a specific result?  Will you be disappointed with a different result?  The face the coin lands on is irrelevant.  In the moment it was in the air, spinning, what did you want it to land on?
• You are considering Deviating from The Path.  Deviating from The Path invites risk, not only of failure, but of scorn.  Look at the dropout, they'll whisper as you pass.  I guess he didn't know better than us after all.  Too bad, really.  He had a good thing and lost it.  Can you endure that?  Do you care?  Does it matter to you, if that's what people think?  Remember that dissent feels like wearing a clown suit [LW · GW].
• Humans are loss-averse.  Tip the scales slightly in favor of the riskier option, knowing that you're in a profession where the worst you'll do is still better than most of the people who have ever lived.
• Do a pre-mortem: you drop out, do your startup, and fail.  You apply to the company you mentioned and are rejected.  You've left college and you've got no job, no startup, no hope.  What went wrong?  What can you do now to lower the probability that it will go wrong, or to soften the blow when it does?
• Sleep on it.
• Sleep on it again.
• Read better advice than mine.

Good luck.

Relevant: Mark Xu's recent (short) EA forum post 'Dropping out isn't a plan [EA · GW].

I skipped college and became a programmer. About 15 years later, I have yet to ever see one single piece of evidence that any employer or recruiter has, at any point, ever had the thought, "I would think better of this candidate if they had a degree." I have had offers from Google, Facebook, and Microsoft (none of which I accepted, so they don't show up on my resume), and recruiters spam me constantly, so this isn't just a tiny eccentric startup thing. Maybe IBM cares. Do you specifically want to work for IBM that bad?

Presuming you can do the usual other stuff to demonstrate your competence and find jobs, which I think is likely if you are hanging out posting dialogues on LW (e.g. you are really good at programming, sharp sounding, publicly visible work, charismatic, willing to approach people) I think you should assume the degree is a totally worthless piece of paper and work from there.

(Obvious caveats: Maybe this doesn't work outside of Silicon Valley culture, or maybe it doesn't work well until you have one job on your resume, or maybe it doesn't work if you don't look like a stereotypical hacker type, or something. I can mostly only speak to my own experience.)

Kudos for writing the internal dialog down! Mine wooshes by so fast, I can never do it. 

I'd point out that your decisions should not be based on "what if AGI..." as the Contra part says. Also, if you are super low to the point of burnout and suicidal ideation, something has to change sooner rather than later. Maybe this particular school or a program is not for you, maybe you are not doing it right, or maybe doing it full time is a problem, or maybe there is something else you have overlooked. It's not a dichotomy stay/leave, there are almost always more options. Consider some creative ones.

It seems to me that the actual problem here is depression. And an important question is whether your model (school will make you depressed, anything else will make you happy) is correct. If it is, then obviously you should drop out, because no diploma is better than diploma+suicide.

But it seems to me that you ignore the possibility of addressing the depression while staying at school, by doing something differently. For example, virtual classes suck, because you spend a lot of time alone. But maybe some of your classmates have the same problem, and some of them might be willing to meet in person, either after the classes, or maybe even some form of "coworking" where you would sit next to each other and watch the same lesson together.

If you think that school is mindless obedience training, wait until you experience JIRA tickets and daily "agile" meetings. Spending 8.5 hours at job, plus an hour or two of commute, means that you leave your home in the morning and return in the evening... how many days of vacation do you get in USA each year? anyway, the latest trend is "unlimited PTO" which in practice means even less... now keep doing this 5 days a week, for 50 years. On the other hand, it's not like you can actually avoid this by staying at school...

Would it make sense to start working on your big project while staying at school? That way, you could get some experience and a diploma, too. If the school doesn't leave you enough time and energy for your own projects, I would guess it will only get worse at a job. Maybe you could start some project together with your classmates.

No matter how you decide, whether you stay or leave -- stay in contact with your current classmates. It is called "networking" and it is how many people get their best jobs.

To me, and I'm not a medical/social work professional, this looks like regular Depression. You allude to your diagnosis, but not your treatment. Are you getting treatment? If not, you should. Like any chronic illness, if left untreated, it could get worse.

So many questions: Are you meeting with a therapist regularly for talk therapy? Have you tried CBT? Are you on medication? Have you changed meds or doses recently? (You seem like someone who would read the fine print: suicidal ideation is a side effect of many psychiatric medications.) And there are activities that have been proven to help light to moderate depression: socializing, excercise (specifically playing soccer), sun exposure, gardening and knitting. (Google them). All of these are worth a shot.

As for the larger picture and preserving your options: take a leave of absence from UIUC, one that will allow you to return if you want later. Don't burn that bridge, which you admit you worked so hard to build. Try an exchange program for the fall, if you can (doing a geographical, that could help with depression, too.) Maybe you'll like studying in a different college, university, or country. Keep working at your startup, but not with the idea that it will fail, but with the idea that it will succeed. And look for that ideal software position that would be the professional choice. Get that lined up, work at it at least for the summer or a semester or two off and see if it is all you dream it to be. Then you'll know whether you want to go back and finish your degree or not.

You do mention outside pressures as reasons for staying in university. You mention family pressure - what is behind that? Is it because they think it's the best for you, or is it for their own prestige? Do they know it's making you depressed and suicidal? Likely they want the best for you, and they might not want you to stay if they know the toll it's taking on your mental health. If it's because it's their dream, not yours, you need to reject it. You can't live another's dream; it's your life.

Then there is also societal pressure to finish university. It's not just hiring managers, today and in the future it's more likely an HR algorithm that will eliminate you before anyone even sees your credentials. Therefore, your career path will be dependent on getting jobs through connections. If you're outgoing and great at self-promotion and networking, this might be realistic. (And you might still be able to use the UIUC alumni network even if you don't graduate, but beware those who are into alumni stuff are usually passionate about their alma mater in a good way.) There are also others in society that will judge you based on your university degree or lack thereof, but those considerations seem less important to you, at least now.

Lastly there is the question of education and experience, which are often gained from attending university, but not exclusively. Another mentions MIT's MOOC -- take a difficult class just to prove you can do it outside the regimen of a professor's timeline. Do you have the skills you need for the career/job you want? As mentioned above, get the job and find out.

I wish you well. I would say, first get help for your depression and then take it from there.

You mention that the benefits of college would be credentials and connections. I don't think it was mentioned in the post that you can also expect to learn a lot during the degree about the fundamentals of Computer Science. Therefore, dropping out involves the opportunity cost of the information not learned in college.

In my opinion, the decision of whether or not to stick with college largely involves a decision to minimize opportunity cost involving a comparison of the opportunities college affords and the opportunities available outside of college. The ratio to be measured is the ratio of opportunities in college to those outside of college. The lower this ratio is, the more reasonable it is to drop out of college and vice versa.