People who work on web browsers have ranted that HTML/CSS isn't a very natural interface into the engine, so it's inefficient and has nasty edge cases. I know nothing about browser engines but do find CSS awkward as a user when I'm not making a plaintext website, so have been relying heavily on React for side projects.

Been thinking about doing a toy project where I try to build my own alternative to HTML/CSS that runs on top of Canvas, drawing inspiration from how Wayland is actually less abstracted than X11.