Reactions-based or high visual fidelity are the main limiting factors I immediately think of. There are many games where these aspects aren’t core to the game

Reactions-based or high visual fidelity are the main limiting factors I immediately think of. There are many games where these aspects aren’t core to the game but there are for sure many where they are. I was pretty surprised by PUBG’s success in the mobile space - Then again I sunk an immense amount of time into Ring of Elysium when it came out on PC and that was in many ways mobile-esque in gameplay and visuals. So there’s probably more crossover potential than I acknowledged in the earlier post. I think a lot of my opinion on the limits of cross-platform (multiplayer) gaming was formed back when Quake 3 got cross-play between PC and Dreamcast. It was an absolute bloodbath.