Comment by imtringued

Wayland is a protocol that can be implemented by a compositor. Since Wayland intentionally chose to only support a subset of the functionality of a display server like Xorg, it became possible to rip out the Xorg specific hardware drivers and make the X11-supporting Wayland compositor known as XWayland possible in the first place.

"We're stuck with just a protocol that can have arbitrary implementations including full backwards compatible X11 servers"