Yes. But for this, Itch needs a major overhaul.
Wrong, the whole point is that user made maps, game saves, friends lists and all that sort of stuff would be implemented game by game. If we passed a UID to web games, you could store all this data (saves, maps, etc) in a database and have it associated with a user w/o each game having a login, sorta like OAuth, but you don’t even need to pass any user data to developers.
User interactions would only happen in game. Very little if any work from itch, other than generating & sending in a UID.
You don’t need to send much of any user data to implement all of this.
the api that already is there is not used?
People develop stuff for other people, there’s no point in putting a lot of time into a cloud save system & friends lists & full multiplayer synced with itch.io if 99% of people on the platform can’t/don’t use it.