That's a nice idea. You could have a simple card-shaped device with no screen or buttons, and call that a "credit card".
“Be kind. Don't be snarky.”
“Please respond to the strongest plausible interpretation of what someone says, not a weaker one that's easier to criticize. Assume good faith.”
At the same time there was also the Exxon-Mobil Speedpass RFID fob, and I remember there being a huge discussion about “the battle of the keychain” and whose payment instrument would win being on your keys to be used the most alongside your loyalty cards.
Like a credit card? They've been around for some time.
Note that the payments are tied to a card/chip but you can (at the moment) buy new card no id/registration required
It was really like digital cash, the money was loaded onto a chip. So if you lost it you lost all the money. There was no pin code either, just like a real wallet. Unfortunately it was not really anonymous because the Dutch government are really into surveillance.
It didn't really last very long, it was only popular for parking machines. In those days 2G was expensive so validating transactions online was rare.