X was a very well designed system IMHO that could be evolved via extensions (e.g. how compositing was added etc.). It is sad that few people work on it anymore to fix such issues.

X isn't opinionated enough, and Wayland is even worse. While X has labels like "substructure redirect override" that in practice means "bypass the window manager" and tries to theoretically support multiple window managers, Wayland barely even knows what a window is!