-Problems with non western input systems
-Accessibility
-Remote control(took around 2 years to be stable I think?)
-Bad color management
Then there's the things that did work in x11 but not in wayland:
-Bad support for keymapping(the input library says keymapping should be implemented by the compositor, gnome says not in scope, so we have a regression)
-bad nvidia support for the first two years? three years?
While these things are compositor/hw vendor faults, the rush to use wayland and nearly every distro making it as default, forced major regressions and wayland kinda promised to improve the x11 based experience.