When you used private, digital cash, even the people who sold you their money didn’t know who you were. Quite likely you had no real idea who they were, either, other than their rates, their market recognition, and their performance history. You had no identity other than your unbreakably encrypted public key word. You could still use government currencies if you really wanted to, and most people did, for the sake of simplicity or through lack of alternatives. Most people had no choice in the matter, because most people in the world were poor.