Wayland is not X12. There is no X12. X is a server. With Wayland, the compositor is a server, window manager and compositor. Wayland itself is a set of protocols and a Wayland compositor is an implementation of these protocols where the protocols and portals essentially replace X and all of its functionality, while ensuring security, isolation, compartmentalisation and extensibility. X11 is an unmaintainable mess. Wayland is just a set of protocols. If an implementation of these protocols, i.e a compositor, becomes an unmaintainable mess, we can just use another preexisting compositor or make a new one. And for applications, you make a Wayland-native app, and it can work of GNOME, KDE, Wlroots, Smithay, etc. (as long as it doesn’t specifically depend on the compositor, like a wlroots wallpaper setter), which means that this app will potentially be able to work forever. And because compositors can only implement whatever they want, meaning that thungs are usually far more minimal and far more efficient than with X11.