It took centuries of trial and error for most countries to come around to their modern systems of money. Central banks today monopolise national currencies, and they steer availability mainly through commercial banks that, as economists often put it, 'create money out of thin air'. That is, centrals expand or contract supply by lending to and imposing reserve requirements on commercial banks. I think cryptocurrencies are going to end up as an alternative option like several categories. It will end up existing alongside traditional forms of old banking.