German retailers have "discount cards", which give you a little off in return for the ability to use your data.
If you pay with a card, they don't need to do that, they already have your info, what you bought, when etc.
No thanks, I want my relationship with shops to be simple: I give you money, you give me product.
And of course cash has the added benefit of being tangible. It's in your wallet, then it's not. Spending more means taking out more bills, or bigger bills.