Earlier quoted context omitted.
Card payments are done through a middleman (Visa, MasterCard) and therefore require a surcharge that's going to a private company. They charge much more than it actually costs them, even including chargebacks etc, which is how they're able to offer things like credit card rewards. In my opinion it was justifiable back when it was new and not heavily used, but now that the economy revolves around it it's just parasiti…
A business can always choose to only accept debit to limit their card transaction costs to near zero.
https://dharmamerchantservices.com/faq/visa-consumer-interch...
Scroll down and check out the debit rates. 22 cents a transaction for credit union debit cards isn't cheap.