This looks interesting, basically it's like a storage layer you own that apps and websites can write to (and read from, if you let them). You can host the storage yourself if you want to, too. @timberners_lee/1045976507611525120
Not entirely sure about this bit though. Unless every website removes OAuth sign-in in favour of Solid, you'll still see "Log in with X" everywhere. A monopoly isn't a great requirement for success.