Debit cards aren't that, in practice, because as you say they typically get the same 3% fee whenever I've asked. Toast and other point of sale networks just charge it based on the network and not the card type.

But even so, I still prefer the credit card instrument, used as a "charge card". For those that don't know, a "charge card" is common with businesses and is expected to be paid off every month. But it helps with managing your cashflow - e.g. you can keep your money in a savings account all month and make one transaction at the end - and it keeps your actual money from being at risk of fraud.

Most Europeans seem confused with how Americans use credit cards for everything, but about half of us use them as charge cards, paying them off every month.

That is a benefit, so I can see paying a small percentage for it, but I don't think that benefit alone justifies the 3-5% of a transaction that credit cards charge now.

As a Canadian , I thought that was the expected de facto way of using credit cards: you pay everything with it so you get rewards (ie money) at the end of the year as a function of how much you used the card during the year. At the end of the month, you pay whatever the outstanding balance is, otherwise you pay high interests.

Debit cards are not subject to surcharging, and any merchant doing so is violating Visa/Mastercard regulations. (And possibly state law in several places -- Colorado where I live caps surcharge at the lesser of 2% or the cost of payment processing.)

You get charged higher prices and then have to use a credit card to recoup the loss, so that rent-seeking monopolists can make money. And Americans are also seemingly baffled by the idea of regulating this away, as if other countries doing this don't exist. Credit cards are the USA epitomized.