A couple of years ago there were some issues with card reading terminals in Germany. Due to a faulty security certificate these card reading terminals were not operational for about a whole month. Many stores were affected, because they almost all use ones from the same manufacturer. The only reason why it wasn’t such a big deal was that people were carrying cash around anyway and were able to switch the method of payment easily. Having cash worked as a backup.
I think it is important to have cash as a backup.
A couple of years ago there were some issues with card reading terminals in Germany. Due to a faulty security certificate these card reading terminals were not operational for about a whole month. Many stores were affected, because they almost all use ones from the same manufacturer. The only reason why it wasn’t such a big deal was that people were carrying cash around anyway and were able to switch the method of payment easily. Having cash worked as a backup.