Like, this is what leads to invasive client-side anti-cheat. Which also happens to be one of the main blockers for OS portability.
But if you make it so that the server has to constantly validate the game state, you get terrible lag.
You really have to design your game well to deter cheaters. And you have to empower server moderators to ban cheaters. This sorta implies releasing the servers so that communities can run their own instances, because these studios don’t have the resources to handle moderation themselves.