It's rather awkward if you come from a country with heavy card use. It's just weird to carry a few hundred euros in cash in your pocket these days.
But credit Cards are coming fast to Germany. Since a few weeks even the cheapest supermarkets, including Aldi, started to accept MasterCard and Visa.
This is not generally true. My credit cards use PIN when the terminal supports it and only fall back to signature when used with older terminals.
I've never heard of online transactions with 1FA auth, most banks use a combination of user login and challenge-response TAN lists or mobile TANs. Special hardware devices that require you to insert your debit card, enter a PIN and have the device read a code directly from the computer monitor using photo diodes are quite common, too.
Coincidentally, I have a Sparkasse credit card without chip+pin. Regardless, there shouldn't be a choice for 2FA.
Finally, is the EC Maestro card from Sparkaasse really a debit card? A lot of online merchants would not accept it.
I think it has much to do with the EU capping interbank fees.