German here. As I've written in another comment in the thread [1], Europe as a whole has
markedly lower adoption for the international credit/debit cards than the US, as most countries have had their own schemes for decades (e.g. Germany's Girocard) so there was no need in practice to get one of the international ones. For vacation, we were used to going to money exchanges anyway so there was no need to get a bank card that worked outside of one's primary country.
And even for those who have credit cards, they are "pay in full at the end of each month" cards, not American-style revolving credit cards. And stuff like the "cashback" cards of Americans, that's also not very common here since the "cashbacks" are actually paid for by the merchant on top of the interchange fee - but there's an EU law that places a hard cap of IIRC 1% on the merchant fees, so there is barely any way for banks to incentivise people to use credit cards.
And on the bank side, here in Europe we also don't really have that "debt holders can just sell off defaulted debts" thing, so banks can't offload the risk of defaults to someone else. And if that's not enough, we also got very strict laws on who can get approved for a credit card and for which limits - stuff like 20 year olds with 20, 30k of credit card debt are truly rare unless the parents of said young people are rich enough to back such a massive CC limit.
[1] https://news.ycombinator.com/item?id=44296338