Cashless stores is something we see a lot in Amsterdam. I always thought that they probably loose a lot of clients, both because of lack of cash and also because they only accept the "pin" card which is, afaik, a Netherlands-only type of debit card.
But at the same time it's also probably safer and less management with accounting done automatically.
According to Wikipedia, the PIN domestic payment network was discontinued in 2012 in favor of Maestro and V-pay debit cards.
The main problem with this is that many countries, even within the EU, don't really issue Maestro and V-pay cards, but rather proper MasterCard and Visa (debit) cards. In my experience it wasn't an issue in Amsterdam. In Brussels on the other hand, I came across a couple places where I could only use my Maestro card.
That said, the unbanked/underbanked population is probably a lot smaller than in the US.
Those pin card are Maestro "compatible" I guess. The card works where Maestro is accepted, but not all Maestro cards work on those PIN systems.
source: I live in Amsterdam and have a Pin card, a US debit Mastercard, a US Credit Mastercard, a dutch debut maestro and a dutch credit mastercard. Only the pin works on those PIN systems
I've been in Amsterdam twice last year, and I was able to pay everywhere with Apple Pay backed by a Visa card (well, almost anywhere, one store required a physical card, and I am not 100% sure Visa would have worked because I used a Maestro debit card there). So apparently most merchants don't limit it anymore - would not make much sense anyway since the EU mandated credit card interchange fees to be below 0,3%. That basically made supporting credit cards almost as cheap as the national payment schemes.
But at the same time it's also probably safer and less management with accounting done automatically.