I'll invoke Cunningham's Law here. If I remember correctly, Wayland was designed to support a wider range of display targets than X11, such as set-top displays, car dashboards, and other specialized systems. In these cases, the full functionality of a traditional desktop environment isn't required, so it isn't included in the base system.
I kinda had this "wayland was actually designed for embedded use cases and [therefore lots of things don't matter]" also in the back of my mind, but I failed to find any evidence at all for this actually being the case. Nevermind that embedded Linux generally didn't use X11 back then and doesn't use Wayland today.
