That is exactly what libraries are for, not protocols.
Should Web Standards mandate the use of a given JS implementation because it hinders the creation of new ones?
Also, the million+1 “de” under X are more like skins, there is absolutely no reason for them to exist in that form, they could just build on top of another wayland compositor.
Okay ? It can be lib. Just make wayland use it, not be thing every DE needs to. DE shouldn't care about where the mouse movement data comes from and should not need to compensate based on device.
That is a correct conclusion, in the same way that many issues with X features are not actually issues with the X server. Over the years a lot of things have been moved out of the X server into client libraries, or into Mesa, or into D-Bus, or into Wayland...
Should Web Standards mandate the use of a given JS implementation because it hinders the creation of new ones?
Also, the million+1 “de” under X are more like skins, there is absolutely no reason for them to exist in that form, they could just build on top of another wayland compositor.