I don't know many people who use credit cards in France. Practically everybody use the so-called CB which is a debit card (either immediate or deferred, usually deferred), not a credit card. It doesn't allow you to accrue debt: the balance is always re-paid in full, and the linked bank account (usually a checking account) will go red in case of overspending.

That said there are definitely credit cards, usually linked to big retailers (Auchan, etc.), but are they that popular?

We never use them as credit card in France. It took me a loooong while to understand, when I lived abroad, why the cashier would always ask me a question when I used my card to pay. In fact I understood later that they were asking if I wanted to use debit or credit. And that felt really odd to me.

And it still does. I still don't know what would have been the point to make a loan to buy a bag of potatoes, but well... Cultural differences.

I meant people use debit card instead. Sure, I can use my us credit card in France after te weird you-need-a-signature-? look, but no-one has credit cards there :-)