It doesn't really. Xwayland is pretty much an X server that draws to Wayland instead of directly to the display. You can write an X server that draws to anythin

It doesn't really. Xwayland is pretty much an X server that draws to Wayland instead of directly to the display. You can write an X server that draws to anything: a display, a printer, a Windows or macOS surface, an OpenGL texture... Xwayland is even based on the same Xorg codebase, it's just that the DDX ("device-dependent X") layer used is Wayland-based.