Credit cards is a money trickling up system. Banks charge the sellers and give a rebate to their customers. Sellers increase their price to compensate for the credit card fees.
And then the poor are denied credit cards and pay the marked-up price on everything, or are given credit cards knowing they will fail to pay back on time at some point and then pay huge interests.
It would be better for most if that system disappeared or was at least severely trimmed down!