I wouldn’t say that screens (protocol term) in X11 are totally useless. In fact, this is how I would implement a more secure screensaver (this would require coo

I wouldn’t say that screens (protocol term) in X11 are totally useless. In fact, this is how I would implement a more secure screensaver (this would require cooperation from the server, though): the screensaver client somehow securely authenticates to the server so it’s entitled to be the screen locking/unlocking process. It’s hosted on a separate X11 screen. When there’s a command to lock the machine, the server switches to that screen. Upon unlock, the server returns to the default screen. Now if you kill the screensaver, or it segfaults because you hit a lot of keys, or a butterfly causes an EMI disturbance and the screensaver dies, you are left with an empty screen and not with your work exposed like in the current scheme of things.