Guess what I'm not getting through to you is that there are disabilities that very specifically affect your ability to "suck it up and work," particularly in an adverse environment. I have one of them.
I'm also a very successful and effective engineer. I've become that by working with my employers to take approaches to work that I can not only handle, but excel with. In doing so, I add significant value, well past the cost of any accommodations made for me.
But when I hit a boss that insists it's done "their way" arbitrarily, to fit their thought process, I'm significantly less successful. You would be too, but the nature of my disability is such that it changes from being impacted somewhat to stopped cold. And to be clear, I'm not talking about shirking work. I'm talking about simple things like making sure that I have somewhere quiet to work, that requirements are clearly communicated and agreed upon, that deadlines are reasonable to the task, and that I have flexibility in how I structure my workday in order to achieve the best results I can.
Nowadays, it's not a problem. I've been around long enough that I have enough clout and experience to carve this out for myself. But early in my career, I did not. I also did not have the diagnosis of the disability (though I certainly did have the disability) and I had some pretty precarious job situations because I was not able to assert this for myself and find ways to be successful. That I managed to get through that was as much luck as it was tenacity, and it was quite a bit of both.
So think of it like this: the ADA exists, in part, to make sure that my professional chances aren't unduly damaged by rigid and inconsiderate bosses. Assuming I'm willing to put in the effort and can give back good results with reasonable concessions, people are required to be flexible enough to allow me to do so. If I ever quit trying for them, I'd expect them to quit trying for me. And if despite all best efforts my work isn't acceptable, I'll go elsewhere. That's the nature of a good relationship, business or otherwise. That's all I expect, and it's all I'm guaranteed.