Isn't this exactly what Chromebooks do? Please correct me if I'm wrong, but they don't run X-Windows or Wayland, do they? And if they did, then what possible benefit would there be over just running the browser directly on the hardware, with the thinnest possible window management and graphics driver layer?

https://en.wikipedia.org/wiki/Chrome_OS#New_window_manager_a...

https://www.chromium.org/developers/mus-ash

https://www.chromium.org/developers/design-documents/aura

https://www.chromestory.com/2012/04/aura-and-ash-in-chrome-o...

http://dev.chromium.org/developers/design-documents/aura/aur...