KDE cannot be modified by extensions in the same way GNOME can. This is a fact. The problem is the extension needed to be written. They are trivial to vibe now. You can make them do whatever you want.
I was pretty sure that was false. I did a quick check and found
https://develop.kde.org/docs/plasma/scripting/
The shell got a lot of hate for being written in gjs, but you won’t get that kind of functionality from a shell written in a compiled language.