Do you think wasm has any chance of replacing the whole html/css stuff with just webgpu in a canvas? I have been playing a bit around with wgpu in rust and I can compile the same project either as a native binary or a .js that just renders to the browser. It seems to work pretty cool. Photoshop seems to be runable in the browser now, and I've seen a lot of other cool stuff, but things like fluid simulations seem to still be very laggy.
Rendering everything into a canvas will realistically mean total lack of accessibility features. Also you won't be able to use the DOM inspector. I don't think that would be an improvement at all. If one could work with the DOM via Wasm (plus source maps so you can still use the debugger) it might be something.