“Screensaver” isn’t a feature of X - it’s functionality provided by XScreenSaver which uses X mechanisms to detect user inactivity, lock the screen and display an animation.
Equivalent mechanisms exist in Wayland, but XScreenSaver doesn’t have logic to interact with them. This can be solved by either teaching XScreenSaver how to talk to these new mechanisms (difficult as it was developed for X from the ground up) or implementing something new.
Network transparency already exists (and has for some time) in the form of waypipe.
xset isn’t a feature of X - it’s a utility to control it. Since Wayland compositors aren’t X, it makes sense for them to be controlled differently.