Yeah, X11 really isn't a Linux thing at all; I think the association is just that Linux distros are the current hacker/poweruser OS of choice, for a lot of reasons including tools that let people do cool/powerful things with the system, and X11 is one of those tools (or the backing framework for them, at least).
I don't know what screen recording has to do with anything? Like, yes Wayland also makes the computer vision half of that example harder (you can do it in all major compositors, but details vary and GNOME is outright hostile to automating it) but Wayland doesn't have an answer to xdotool which is arguably the bigger component. (I am aware of tools like ydotool and such, but AFAIK they're all significantly weaker; they can blindly inject emulated key/mouse events, but not, say, target specific windows)