> I don't think Wayland ever supported
Isn't that true for even the most basic features you expect from a windowing system? X11 may have come with everything and the kitchen sink, Wayland drops all that fun on the implementations.
GNOME does unredirect on Wayland since 2019: https://www.reddit.com/r/linux/comments/g2g99z/wayland_surfa...
> Windows killed it
They replaced it with "Fullscreen Optimisations", which is mostly the same, but more flexible as leaves detection of fullscreen exclusive windows to the window manager.
https://devblogs.microsoft.com/directx/demystifying-full-scr...
As far as I can find the update removed the option to turn this of.