[notahacker]

People have only been paying with coins for six or so millenia now...

(And of course the reason bank credit has more recently become treated as currency and accepted as electronic payment is because it's exchangeable on demand, at parity to and often instantaneously for legal tender)

[grondilu]

When you exchange coins physically, the payment method is ... your hands.

> bank credit has more recently become treated as currency

A bank credit is not a currency. The thing it is denominated into (EUR, USD, BTC...) is.

> And of course the reason bank credit has more recently become treated as currency (sic) and accepted as electronic payment

I think the real reason is that people had little to no choice in that regard.