Weird. In Germany, it's usually very, very fast (recently, using my Number26 CC, payment in three seconds including PIN entry, and ten seconds later I got the push notification on my phone).

But that may also very well be because it's rare here to see outdated terminals. Most retail chains change their card terminals every two or three years, because they listen to their customers who actively demand speedy transactions. Oh, and because stores usually don't own the terminals but rent them (cheapest solutions are at < 20€/month and terminal). Downside: CC fees for merchants can range up to 4%, most of it goes to the CC providers.

It mostly seems smaller merchants simply don't switch their acquirer to get cheaper rates and complain about "high costs". FWIW, credit cards are capped at 0.3% interchange (which is what the bank gets), debit cards at 0.2% since last year. Scheme fees for MasterCard/Visa are peanuts and even AmEx doesn't cost 4%.

For example see https://www.cashforless.de.

Visa/MasterCard credit and debit 0.98% German debit (girocard) 0.25%

The only terminals in the US that take the chipped cards are brand new (because the cards themselves are new and the deadline to accept them isn't quite here yet). I don't know why they are so slow, but they are all brand new machines.