I don't think your impression of American shopping is accurate.
Many people pay with credit cards because they don't want to deal with loose coins and because credit card transactions can be viewed online. Anything I put on my Visa card I pay off in full at the end of the billing period; there are no fees, charges, or changes in prices that hit you when you use a credit card.
We too can use debit cards that way. The laws regarding fraud liability differ between debit and credit. As such, credit card providers generally have fraud detection departments working around the clock, whereas the onus is entirely on you to report fraudulent charges on a debit card within so many days of the charges appearing on your monthly statement.
OTOH there's the hidden cost of transactions, which the seller pays (and that's where the refunds come from), which admittedly won't go away if it's just you who stops using credit cards.
Many people pay with credit cards because they don't want to deal with loose coins and because credit card transactions can be viewed online. Anything I put on my Visa card I pay off in full at the end of the billing period; there are no fees, charges, or changes in prices that hit you when you use a credit card.