Sorry guy, but this is really a new low in unreadable rants, even by your standards. I will try to comment on some of the parts that I could actually decipher:
Their only aria-label example on that page is of an input without a label. I don’t know where you see duplicate labels, but that page really has only one. Same story with the aria-required, the only place where it is used is on an input that is not made required with html (which is pretty normal if you have JavaScript validation). And yes, they don’t reinvent every accessibility standard. And why on earth would they? That wouldn’t add anything to what already exists and it is none of their concern. Rewriting the entire WCAG would just be a waste of time.
JSX and template strings are not comparable in any way that matters, an AST is not a string. Getting basic stuff like this wrong might be an indication of who here needs to work on their knowledge, but I will leave that judgement to your own reflection skills. Only I find it hard to take someone who claims to know it all better seriously if they keep getting simple first year uni stuff wrong.
In React you do indeed use the on-events attributes. But as you already said, that is not how it is after compilations. This code style is part of the reflective programming paradigm. You don’t have to like it, but calling an entire paradigme with lots of scientific backing crap sounds a bit ridiculous to me. Not everything you don’t like is neserly bad, thinking like that is a pretty big sign of a God Complex.
‘htmlFor’ and ‘className’ are indeed two small differences in syntax that are needed because ‘for’ and ‘class’ are already reserved keywords in JavaScript. Using those in the JSX specification would break a lot of tooling, which can be easily avoided by not treating the html specification like it is the Holy Bible. See it as the lesser evil if you want. BTW, keys also don’t get into the output. They are just there so you don’t have to bloat you html with unnecessary ids.
Last but not least: React doesn’t rebuild the DOM on every change! This is the most fundamental thing to know about React (and every other modern frontend framework for that matter). The virtual DOM is what gets (partially) rebuilt, not the real DOM. The real DOM only gets updated with the diff of two. That you still don’t seem to get this point after spending hours of ranting about it is staggering me, it isn’t that hard to understand (or is it... ?).
Like you can see, most of the stuff you see as bad just boils down to a lack of knowledge about very basic programming concepts. Just for love of god, try to do at least a little bit of research before you decide everybody else is an idiot and build your own truth in a bubble of ignorance.
