The point is: The libraries are not from the same people that build the standards, meaning: there is no "primary implementation" that everyone agreed on. ("agreed on" already is one of the problems, X11 was mostly just developed and everyone got "the thing" and had to use it, for better or worse. In Wayland, KDE, Gnome, wlroots, etcpp first have to agree on a common protocol to implement... and we see how that is going)