They are not banned. They are heavily regulated in many European countries.
In several of them:
- Cashback systems are simply banned.
- Credit card are by default Debit Card. The credit option need to be opt-in.
- Credit Card payments spread over several months are discouraged or simply banned by default.
Credit cards are also much more rare.
With an average of ~1 Credit Card per inhabitant in some countries. Where the US average is ~4 Credit Card per inhabitant.