I wonder how this is true "people hate to wait on someone paying his chocolate bar with credit card". In the US, I always wish they had non-cash lanes at groce

I wonder how this is true "people hate to wait on someone paying his chocolate bar with credit card". In the US, I always wish they had non-cash lanes at grocery stores (especially at Costco, Walmart) because paying cash is almost always a super slow process. Do prices and taxes in Germany for stuff usually end up in whole numbers? I think in that case it's easy to calculate total owed and be ready with the exact amount of cash.