Getting diagnosed for ADHD if I don't plan on taking meds?

"Diagnosed" isn't a clear concept.

The minimum viable "legally-binding" ADHD diagnosis a psychiatrist can give you is to ask you about your symptoms, compare them to extremely vague criteria in the DSM, and agree that you sound ADHD-ish.

ADHD is a fuzzy construct without clear edges and there is no fact of the matter about whether any given individual has it. So this is just replacing your own opinion about whether you seem to fit a vaguely-defined template with a psychiatrist's only slightly more informed opinion. The most useful things you could get out of this are meds (which it seems you don't want) accommodations at certain workplaces and schools (as Elizabeth describes in her common), and maybe getting your insurance to pay for certain kinds of therapy - but don't assume your insurance will actually do this unless you check.

Beyond that minimum viable diagnosis, there are also various complicated formal ADHD tests. Not every psychiatrist will refer you to these, not every insurance company will pay for one of them, and you should be prepared to have to advocate for yourself hard if you want one. If you get one of these, it can tell you eg what percentile you are in for various cognitive skills, for example, 95% of people are better at maintaining focus than you are. Maybe some professional knows how to do something useful with this, but I (a psychiatrist) don't, and you probably won't find that professional unless you look hard for them. 

If you already have a strong sense of your cognitive strengths and weaknesses and don't need accommodations, I don't think the diagnosis would add very much. Even without a diagnosis, if you think you have problems with attention/focus/etc, you can read books aimed at ADHD people to try to see what kind of lifestyle changes you can make.

In very rare cases, you will get a very experienced psychiatrist who is happy to work with you on making lifestyle/routine changes and very good at telling you what to do, but don't expect this to happen by accident. You're more likely to get this from an ADHD coach, who will take you as a client whether or not you have an official diagnosis.

The big thing an official diagnosis gets you besides meds is accomodations from organizations with HR departments. There are other useful things that come from knowing you have ADHD, but they normally don't require a credentialed note. 

That said: I know multiple people who didn't think an ADHD/autism/anxiety/depression diagnosis would do much for them but ended up being really glad they pursued it. It can be hard to know how helpful a given intervention or just the satisfaction of having a label will be ahead of time. ADHD diagnoses can be a lot of work to get and have some downsides, so this isn't a blanket recommendation to pursue one, just a suggestion to consider the full confidence interval of how useful a diagnosis might be, rather than the median.

There's a lot of value in going to the doctor and talking about your symptoms and how your patterns of thought and behavior are impacting your life and relationships.  

Whether you "get diagnosed" or not is a secondary choice - perhaps at some point trying out medication will be attractive.  Or perhaps not, but a professional diagnosis may give you more of a handle to recognize the aspects you'd like to change or overcome.  

Or you may find that there are other diagnoses that are more helpful to you, which a doctor can consider and the "several people" aren't aware of.

Or perhaps (like me), your doctor will say "yeah, you can have a diagnosis if you like, and I'll work with you to find the right meds which help, or you can not worry about labels and we'll just find techniques that can mitigate some of the habits and effects of your individual situation, whatever the reason."

I do take medication, because it does help me be more evened out, with fewer days where I can’t work, less social anxiety, way fewer shame spirals. That is just for context.

Getting an objective test, administered over the course of several hours, by an expert really sort of freed me from doubt about whether my symptoms are personal weakness. It allows me to be okay with the fact that chores come in bursts, and I can never finish projects.

It’s brought me a lot of peace.

I was in a similar position, but I am now at a point where I believe ADHD is negatively affecting my life in way that has overturned my desire to not take medication. It's hard to predict the future, but if you have a cheap or free way to get a diagnosis, I would recommend doing so for your own knowledge and to maybe make getting prescriptions in the future a smidge easier. I think it's really believable that in your current context there are no or nearly no negative repercussions to your ADHD if you have it, but it's hard to be certain of your future contexts, and even to know what aspects of your context would have to change for your symptoms to act (sufficiently) negatively.

First you would get a breakup of the particular strengths and weaknesses that you have (similar to getting an IQ test it is not just a number but the breakup into areas of strengths and weaknesses can be quite useful).
 

Second they would be able to help with strategies to deal with the ADHD.

Third it gives you optionality about taking meds i.e. it gives you the option to try them lateron.