That's for credit cards, debit cards penetration is much higher, my guess from working in a big fintech previously is that around 85-90% of people with a bank account in the EU have at least a debit card.
Are European debit cards maybe somehow different than US ones, and the experience differs between the two?
Sure does! Just signed up with BBVA some months ago and got a Visa debit card from them called "Aqua". https://www.bbva.es/en/personas/productos/tarjetas/tarjeta-d...
The only places I've found that only accept credit cards are hotels.