Depends on everybody needs obviously, but say you have your dev machine that is remote, and you want to connect to it from a laptop (for real-estate reason or just for working from everywhere you want), maybe you want everything on the same (remote) machine like browser, db, IDE, etc and access to it as a remote "desktop" not just an ssh session.

Of course cli tools would be enough for somebody who likes a full TUI dev environment (and for my own use cases that would be enough) but for some people I understand the need, and I feel it is a regression for them to not have it.

I have not used Wayland specifically, but did do this for X11, Windows, Qt, too much stuff to count... It usually takes the form of an api call like

DispatchEvent(&MouseEvent{MOUSE_L, 1345, 3432});

It's almost literally always this