I don’t doubt that they exist, I’m just struggling to think of a popular example.
I did a similar thing with X11, but I didn't like so much.
Bit by bit, Apple is loosing it's Desktop position. It all starts at the developers. At soon, every person will be a "developer".
The dependency list is also...something: https://github.com/J-x-Z/cocoa-way/tree/main/vendor
It would then essentially run android on macos as well, I do feel like it should be possible.