It's really up to app developers to make sure their apps work ok (provide fallbacks if gesture heavy) for mouse.
I think we are in a period where Android is just starting to get used with mouse so I'd expect it to take a bit of time for things get in shape for mouse users.
Understood who should really address the problem, but if RemixOS doesn't have an interim solution we might see the same catch-22 here as we often do. App developers will care about these things when it matters commercially, and consumers will care about them when the apps work.
I can use the mouse on my android box ... the issue is that the things you have to click don't make sense with a mouse. E.g., there'll be two buttons, one on each side of the screen. Easy to hit with two thumbs, impossible to hit with a mouse.
I think we are in a period where Android is just starting to get used with mouse so I'd expect it to take a bit of time for things get in shape for mouse users.
Some apps work better than others