I saw a really cool concept for "Anti piracy" some time ago. It works by having a lot of little achievements which represent you progress. So each time you start the game it checks for which achievements you have and the loads your progress according to your achievements.
So, basically cloud saves with extra steps, except you only get a single save and can't replay the game? Sounds even worse than current solutions, honestly
Performance isn't the only issue. This system would also not let you play offline, without being logged in and you couldn't have mutliple saves or replay the game.