I am blind. I do rely on accessibility to interact with a computer. Yes, you could accuse me of deliberately avoiding the modern web, but I have my reasons. Primary reason is performance. Even though I feel like you are talking down to me from a pretty high horse, I still don't wish for you to ever experience how sluggish it feels trying to use the "modern web" with a screen reader on something like Windows. Don't even make me start about the hellhole that is Linux GUI accessibility. It was a nice ride once, before GNOME 3 and the elimination of CORBA killed most of the good work done by good people. Fact is, I am too used to a system which reacts promptly when I press a key to be able to switch to a modern browser by default. That would kill all my productivity. Yes, its a trade, but for now, having no JS engine by default is still way better then the alternatives.
I apologize for saying your use case is incorrect-- clearly, someone using a screen reader would have a totally legit if still comparatively uncommon use case. I have used the modern web in screen readers because I've developed modern web pages to be accessible, which by my estimation means doing more than using a WCAG scanner.
I still think it's ridiculous to say that developers are doing something wrong by using modern practices just because it doesn't fit your use case. You can have your opinion all you want to and I can have my opinion about it.
Have a nice day, and enjoy your eye-sight.