Are we talking about the same Germany? There are extremely few toll roads (as in: most Germans will never use one in their life) and uniformly across the country, small shops (such as bakeries and food stalls) operate on cash only. Basically mostly national chains take cards, for the rest it's hit and miss.

In other European countries things look different: On the other extreme is Sweden which I visit regularly. I couldn't even tell you how their cash looks like because I haven't used any for a long time.