That's the crux of the matter isn't it? They want to have a JavaScript framework, but when you run it in the browser, all the accessibility issues pop up and additional workarounds are needed, to get the default browser stuff working properly again. We all have seen the many many websites, that break the back button. So they move rendering back to the server, where it was before, with traditional templating engines. But oh, now it's not so nice any longer? Could it be, that the whole approach is not actually that great? Could it be, that a traditional templating engine with a tiny js framework, that is only served on pages when needed and only does little interactivity aspects would serve us better in almost all cases of websites?

I think React and JSX and custom components as they are in React with JSX have people "programming" things, that don't need that kind of programming, as they are static things, that do not need the power of a full blown programming language behind them. In a way JSX is even more cumbersome than some PHP, because it makes you learn a new wannabe HTML syntax, which is not HTML (for example classList instead of class) for little benefit on most websites.