Why I can't address this for Android.

There's no app for that unless you count VNC.

ACTUAL Experience is VNC for a demo where we needed to show the screen during the demo. But it's far too fiddly and it FAILS for you in a few ways.

As a hardware and software designer and author (I do write stuff!) I know some of the stuff underneath.

So why isn't VNC a fix for now? I'm only guessing you don't want the PC on the other end.
Bob