Screen sharing and screenshots weren't an afterthought. Weston had support for those for a long time, but gnome and kde decided to do something different, probably because they saw pipewire was maturing.
Allowing arbitrary clients to globally capture keys at will is impossible to do without opening up a hole for keyloggers. Maybe someone will figure out a good way to do this but I wouldn't hold my breath. You're better off writing a compositor extension to do what you want.
The CSD-vs-SSD debate isn't anything new, there were apps that used CSD before wayland, and there were X11 window managers that didn't draw any window decorations. There is fragmentation there but it's caused by the apps, you won't fix that one without rewriting all of them to have the same policy on decorations, probably that means redesigning all of them to use the same widget toolkit and designs.
Allowing arbitrary clients to globally capture keys at will is impossible to do without opening up a hole for keyloggers. Maybe someone will figure out a good way to do this but I wouldn't hold my breath. You're better off writing a compositor extension to do what you want.
The CSD-vs-SSD debate isn't anything new, there were apps that used CSD before wayland, and there were X11 window managers that didn't draw any window decorations. There is fragmentation there but it's caused by the apps, you won't fix that one without rewriting all of them to have the same policy on decorations, probably that means redesigning all of them to use the same widget toolkit and designs.