Well, it’s clearly what the Google docs team wants. And it would yield higher performance for other similarly complex web apps (eg Figma). And allow native UI development in more languages (Blazor). It also looks to be the sort of thing the Flutter team want for web builds. And it could work well for the base system of chromeOS too.
For whatever reason, Google invests hundreds of millions each year into chrome, and trusts their engineers’ leadership on how to make it succeed. The question in my mind is if browser engineers themselves decide to push in this direction.
Chrome has been pushing Houdini [1] for years. It doesn't have special WASM integration right now AFAICT but it is basically a lower level layout & rendering API for the browser.
I've looked at Houdini again and I'm not convinced.
First, because it's more like OpenGL 3 (add more powerful APIs) than Vulkan (clean room design).
Second, it seems mostly abandoned. The page you cited lists multiple sub-proposals that have "No signal" even from the Chrome team. All mentions of Houdini I can find on developers.google.com are from 2018. I can't find anything about Houdini integration with WebAssembly, which is what I'd expect if development was ongoing.
Overall, I'm seeing everything I would expect to see in the timeline where Mozilla has no intention of ever implementing Houdini, and Google has decided it's not worth pursuing beyond what's already implemented.
For whatever reason, Google invests hundreds of millions each year into chrome, and trusts their engineers’ leadership on how to make it succeed. The question in my mind is if browser engineers themselves decide to push in this direction.