Comment by ericmay

In some cases different Visa or Mastercards have different fees associated with them, and if the merchant has configured or negotiated with their service providers to only accept cards under a certain fee percentage then just being a Visa or Mastercard is not enough. One example I can think of is the Chase Sapphire Reserve card as that is (or was I guess things can change) a Visa Infinite card and I believe transaction fees are closer to ~4%> or something versus maybe a standard ~3%. I don't know the exact fee percentages but that's the mechanism.

I agree the reality is a bit more complicated and even wrote about it in France when dealing with gas stations but what I wrote is broadly true. You can just take a credit card to Europe and the vast majority of the time you just won't need cash. I also agree it's a good idea to have a couple of cards though and maybe your debit card too. Frankly I do this in the US as well, and not just when traveling abroad.