Wayland isn't broken it's new. Let's take, say, global shortcuts: Doing it the X way means that if you can display a window, you can keylog the whole desktop. That's not acceptable in a modern design, so wayland clients are isolated from each other, and the wayland devs simply left it out, saying "if people need this, they can come up with a protocol extension to do it properly". Then, years later, desktop environment devs came around and said "hey, global shortcuts, what about that" and spent two years hashing out a protocol to do it, one that will stand the test of time. It in fact didn't become part of wayland but xdg-desktop-portal, a collection of protocols started off by the flatpack folks to enable interaction across sandbox boundaries: The application doesn't say "hey x server, give me all keyboard input everywhere" but "hey wayland compositor, if it wouldn't be too much bother and it's fine with you I'd like to react globally to this key combination".

And then random software comes along and refuses to implement things and users complain that everything is broken. Yes, code will have to change application-side for Wayland, unless your app doesn't do a single call into Xlib but does everything via toolkit there's going to have to be changes. But what did you expect you're using a library that's fucking 40 years old. A library that was written with the devs fedexing source back and forth because the internet was too unstable to reliably send two or three megabytes over night because it was still a research project.

...and along also come random desktop environments and their devs unwilling to implement standards for absolutely no reason. Not just mostly but pretty much exclusively Gnome. This mpv commit captures the opinion of the wider community quite well. (mpv's main gripe is gnome's lack of support for server-side window decorations, with the gnome devs going "tell your tk to draw them" -- mpv doesn't use a tk and is not about to start to link to one just to draw decorations which the server can do better because mpv couldn't care less how they look or what buttons they have).