I can go almost anywhere in the world and use my own form of electronic money: credit cards. Many people are using their phones and in some stores, you simply walk in, pick up the items you want, and leave. The store recognizes your face and bills your account. Yes, you need currency to pay that account. But that transaction happens “behind the curtain.”

John Maidlin, Thoughts from the Frontline 07-22-2019 https://www.mauldineconomics.com/frontlinethoughts/money-of-the-future