The difference is that x11 was SK bag that you required a tons of plugins to have a working system(xorg) and no one could reliable maintain that mess of codes and plugins where every change could break another
The extension situation is already much worse in Wayland than in X11. In my X11 server there are about 25 extensions and only a handful are required for modern desktop functionality. Wayland already has well over a hundred extensions (protocols) and dozens of them have to be implemented by each compositor just to get basic stuff working.
I have a news flash for you, the situation with extensions in Wayland is ten times worse than X11. Wayland requires an extension for what used to be considered basic functionality in a desktop environment.
