Valve has everything you want and guess what happen to Steam, it became a place where scammers get money. There is also laws about loot box that first time indie developers don't even understand and Steam themselves had to change because of laws.
Itch.io can not go to the same route like Steam with it's many mistakes including parts where the government gets angry. It is just better to never add those features in the first place. You still can do the same thing with servers but not with itch.io help.