The Lens That Sees Its Flaws
"I don't think it's necessary for each individual to be aware of their own irrationality or try to become more rational or what have you."
Necessary? True. Human civilisation has progressed quite far without rationality taking an obvious, prominent stand at it's forefront. I wouldn't even say that making rationality worldwide would make life for the average human easier enough to use such a stance as marketing for rationality.
But, you are forgetting a rather, in my opinion, obvious benefit of rational thinking: the efficiency of rationality.
Suppose I am confronted with a man who was raised believing bananas induce insanity. How can I convince him otherwise? If neither of us are advocates of rational thinking, it could devolve into a shouting match with both of us believing the other completely insane. This is speculation, here.
If I'm an advocate of rational thinking, I might suggest experimenting with feeding bananas to previously confirmed sane people as a way to prove him wrong, if I don't think there's a chance of him being right. This taking more time than a shouting match. If I decide to approach the issue with the caution of a scientist, I'd need to approach the issue slowly and cautiously, because I'd need him to monitor my experiments, taking even more time than a shouting match.
If we are BOTH rational thinkers, a simple discussion about how many billions of people should be somewhere between frothing at the mouth to ticking homicidal time-bombs(depending upon his personal definition of insanity), taking about the same time as a shouting match. And(hopefully!)leaving him with the conclusion that bananas do NOT induce insanity.
I dare you to argue with rationality's efficiency.