The story of Wayland - restrict what applications can do in the name of "security" only to re-add the same thing in a compositor-specific way after years of pain inflicted on everyone. Wayland is fundamentally designed for the smartphone model and has no place on an open desktop.
I agree with the Wayland premise that having an old and hairy library everybody is afraid to touch is bad, but having those same capabilities implemented piecemeal and incompatibly by five (and counting!) compositor ecosystems in ways that aren't well-tested or well-integrated isn't better.