X/X11 is a client-server protocol from the age of 10Mbps networks, intended for a bunch of "dumb terminals" connected to a mainframe that runs the apps, with several "optimizations" that over time have become useless cruft.
Wayland is a local machine display system, intended for computers capable of running apps on the same machine as the display (aka: about everything for the past 30 years).
Nowadays, it makes more sense to have a Wayland system (with some RDP app if needed), than an X11 system with a bunch of hacks and cruft that only makes everything slower and harder to maintain. An X11 server app acting as a "dumb terminal", can still be run on a Wayland system to display X11 client apps if needed.