Come to Berlin and marvel at how many cash-only shops we have.
And if you are talking about internet retailers, can we make an exercise to think of how many new businesses would be viable if transactions of 20 cents were a thing?
10 years ago I remember either MediaMarkt or Saturn (large electronics/ home appliance stores) not taking credit cards. Now not only most businesses in Berlin take credit cards (I saw a couple of cash-only, for sure)… I found a couple of “electronic payments only” ones.
A lot of shops started to accepted cards because of Covid restrictions, leading to the point of "contactless transactions". Now that restrictions are being lifted, smaller shops are going back to cash only or putting high minimums.
Two explanations I've heard: (1) small-shop owners simply do not want to pay the fees to card processors and (2) people are more privacy-minded here and distrustful of both the government and the banks, so they don't use credit/debit cards for purchases as often.
The customer chooses the mechanism, not the merchant. To best credit cards you'll have to be more customer friendly.