This is a pretty neat idea, and shows that maybe a desktop environment could be a lot more flexible than we're used to if it was based on something flexible. Not exactly counter intuitive.
I'd like to see how complex a CEF-based Wayland compositor would be in comparison.
How about using Godot instead of CEF? It has a pretty full-featured UI system.
So many possibilities.
While you're at it, go on a huge tangent writing a library that allows one implementation to work as both an X11 and Wayland compositor.
Actually why stop there? Make said library also compile to a full screen Windows and Macos application that somehow renders the contents of windows to textures and does event handing etc. that way you can write your desktop environment once and use it everywhere.
I've gone crazy with power.