My hunch is that someday crypto will be accrued and used like frequent flyer miles or credit card rewards points. But the "better than any alternative" part is that they'll be more fungible than rewards points.
Frequent flyer miles are just a marketing gimmick. They're not "useful" as in serving an irreplaceable purpose; frequent flyer miles could be outlawed tomorrow and the world would not be a worse place in any way.
