Bitcoin doesn't need anything physical to be backed with, scarcity has now been achieved digitally. I know the grandpas out there struggle to get this one.
Agree with the first part, but scarcity itself does not make Bitcoin into money. I would say it does have backing, not by something physical such as gold, or by the state, but by its expanding network of users.
Well, fiat isn't scarce and is considered money because people use it to acquire goods and services which is all that matters for it to be money. But we can talk about what makes money quality money, and quality money needs to be scarce.