Replacing something featurful with something minimal is silly.
Unless those features just plain don’t work well in the 21st century. Looking squarely at X11’s network capabilities here, most of which were designed before encrypted remote access became the norm.
There is no such thing as a ‘stable’ Wayland interface. Each compositor is responsible for their own interfaces, the Wayland protocol is there to make sure that applications written for Wayland play nicely with them.