That is NVIDIA’s fault. They wanted everyone to use the inferior EGLStreams while knowing GBM is better. Everyone ignored them and moved on, so NVIDIA sucks on Wayland. They did change their mind recently so maybe you’ll get support at some point in the future. Unfortunately there’s nothing to do from the Wayland side to fix this, except for adopting EGLStreams which nobody will do.
There’s no protocol yet that allows apps to observe inputs. They just started working on it so it may be a while.
Steam is not Wayland compatible. The games you are playing are most likely not Wayland compatible. This is not a Wayland issue.
It won’t need to for much longer. The protocol for screen capture was merged weeks ago.
That’s NVIDIA’s fault for refusing to adopt the agreed upon methods for rendering graphics on Linux. They tried to force EGLStreams on everybody for almost a decade while knowing GBM was better.
The screen capture protocol was merged a month ago. Support will come soon. wayvnc, grim (and by extension grimshot) already have support for it. No compositors have implemented it afaik, but wlroots is very close to it.