And then they only work on wlroots rather than every Wayland compositor, and then we're back at the original part of the problem that wlroots now had to reimple

And then they only work on wlroots rather than every Wayland compositor, and then we're back at the original part of the problem that wlroots now had to reimplement the parts of X11 that were deemed safe to remove, but were later found to be used enough to be required. The difference is that on X11 since it's part of the standard it will work everywhere, rather than only with one window manager.