Someone in the food chain does take less in some EU countries. Not all.

The commissions are capped by law in some parts, but not others.

As a small sample, in RO i think a large store chain pays like 0.5%. The consequence is credit card reward programs are either non existent or something like 0.1% cashback. The other consequence is you can pay by card almost anywhere.

On the other hand I've been to NL and small stores simply did not take Visa/MC because it was too expensive for them. Guessing the visa/mc charges weren't capped there.