Credit (and debit!) cards solve the trust problem of online shopping and as such are vital to competition: I know I can get my money back if I don't receive goo

Credit (and debit!) cards solve the trust problem of online shopping and as such are vital to competition: I know I can get my money back if I don't receive good or services anywhere; if that weren't the case, I'd probably only shop at a very small number of highly trusted merchants. Credit cards, in the US implementation where the issuer collects ~2% from the merchant and pays their cardholder a kickback from that, are both a cost to cash payers and very inefficient in general, but that's not the only way of doing things. The EU capped interchange fees at 0.3%/0.2%, for example, and purchase protection is still available just like before.