Separation of responsibilities is something Wayland fails hard, by effectively hardcoding coexistence of significant part of display driver, windows management, simple things like windows decorations (which, thanks to Gnome's insistence, are by default only client-side, so your concerns invade internals of client apps!) etc.
Just don't use Gnome. KDE is fine with server side decorations and it's false that Wayland mandates client side ones. Wayland ≠ Gnome and Gnome itself indeed made a bunch of pretty questionable decisions.
But if anything it's X11 that tries to lump a ton of stuff together. Wayland is very minimalistic in comparison. That's why stuff like libinput and Pipewire are part of making a functional desktop.
Client Side Decorations are made effectively essential in core protocol (given that the core protocol doesn't even support existence of "windows"), server side decorations aren't, and some applications will display weirdly because of that.
More over, every "WM" in Wayland's case needs to implement the entire stack, even if it uses a common library for some of it.
And after similar length of development time, I'd say the result is still worse in many aspects than X11, and I say that as someone both using and praising a wayland-based compositor and lamenting that it pretty much locks me more than Windows used to