[rcxdude]

It's not impossible, but it requires extensions to the protocol. Historically the main headache is that support across different compositors was inconsistent, and may not even use the same extension, which means a developer looking make such a tool would need to in practice need to implement many different interfaces to make it work, which tended to mean it didn't happen (I think most devs kinda get as far as looking at the interfaces, seeing a bunch of drama between different compositors about what the correct way to do it is and whether it should even be done at all (GNOME), then decide to go for a nice walk instead). I think screen recording is now reasonably well supported and standard, I don't know about input interception and simulation.