Anything that holds value can be used as money. Digital money is simply a ledger recorded on a computer. Cryptocurrency uses a encrypted ledger maintained on a distributed network of computers.
Since anything can be used as money, I suspect the ideal economy is one people can use whatever they want to use as money.
The world has been using a form of electronic money for some time. The central banks make loans to member banks. These member banks then loan to the world.
This loan based system has the unfortunate habit of concentrating wealth in a ruling elite formed around the central banks.
The hope of crypto is that by creating a centralized currency, we might be able to turn around the process of centralization.