Maybe your sample is really biased, but the actual credit card ownership rate in Germany in 2017 was 53% and growing YoY, so it's likely quite a bit higher by now.
https://www.statista.com/statistics/865943/credit-card-owner...
You may need to copy & paste the title of that page into Google and access the page from there to see the data.
> "You know, China, much of Africa ..."
Oh, you don't even have to go that far. Of all the people I know maybe 1 out of 10 has a credit card. The irony in regard to your post: Most of them got one because "it was needed for something online" at some point. This is in Germany.