> For US readers - in my country in Europe I'd say that 95% of people have only debit card, not credit card. it's very not common to have a credit card here.

In the countries I've been to in the EU (Belgium, France, Spain, Luxembourg), when they give you cards they give you typically both a debit and a credit card. It's extremely common to have both. I've got debit cards, a pre-paid debit card (which I top up when I plan to spend) and credit cards.

And getting up to 2% cashback in the EU (even if the fees vendors can add in the EU are maximum 0.3) is not that hard.

It's very common to pay for mostly everything with a debit card and then use a credit card to, say, book a plane or vacations or to open a tab when you check-in at some hotel.

Heck, I don't even know if you can book a plane with a debit card!? (and anyway then you probably don't get the cancellation insurance etc. that you typically automatically get with a credit card).