> X11 for desktop window management (think how your windows layer on top of each other)
That’s not really the primary job of these protocols - they are primarily about interfacing with GUI apps and displaying their content — compositing those contents on top of each other in one way or another is the job of a window manager, which can be in-built, or separate from the display server.
> Wayland still doesn't support a lot of the functionality even from the desktop perspective
This has been less and less true. Plenty, or even most distros ship with wayland by default and people don’t even realize it. Under gnome which is arguably the most complete implementation I really have a hard time listing things that don’t work.
That’s not really the primary job of these protocols - they are primarily about interfacing with GUI apps and displaying their content — compositing those contents on top of each other in one way or another is the job of a window manager, which can be in-built, or separate from the display server.
> Wayland still doesn't support a lot of the functionality even from the desktop perspective
This has been less and less true. Plenty, or even most distros ship with wayland by default and people don’t even realize it. Under gnome which is arguably the most complete implementation I really have a hard time listing things that don’t work.