[TillE]

To clarify, you can rely on nearly any supermarket or drug store to accept credit cards / contactless these days. Daily shopping is no problem.

Smaller stores or restaurants, forget it. Bring cash.

[cyxxon]

It has gotten much better in the pandemic. I pay at the bakery etc with cards. Not sure when I last paid enything with cash. Only caveat is that "cards" not always means Visa/MC/AmEx, but can mean Girocard only. If that is the case (and I'd just ask) then you as a non German will have to pay cash.

[jacquesm]

In restaurants it just so happens that not all of the people are on the books and neither is all of the income.