[wereHamster]

I don't believe WebGL is suitable for rendering applications. Look at game UIs, they usually are either crap (low-cost games, where devs didn't sped too much time and simply blit button sprites somewhere on screen), or the authors had to implement a widget set on top of GL (WoW comes to mind). But a widget set is exactly what React and web components give you (built in top of basic building blocks like divs and spans and of course CSS for styling).

And while HTML was initially created for hypertext documents, it doesn't mean it can't be used for somthing else. I disagree that it's an ugly hack. Some parts may not be suitable for GUI apps (uhm, like <blink>), but then simply don't use them in your application. Or implement something better on top of the good parts (like React did). Eventually the good parts may be come standard.