Its just very convenient due to being basically a one-click payment. I think the big difference in Germany is that people here tend to have their bank account

Its just very convenient due to being basically a one-click payment. I think the big difference in Germany is that people here tend to have their bank account linked with PayPal, not their credit card (because many people in Germany don't even have one). Compare that to entering your "up to 34 alphanumeric characters" IBAN bank account number manually while on your phone.