Actually, americans didn’t see any difference because the majority use iphones and apple pay requires pin/fingerprint/face recognition for every purchase. This unlike Google, which lets or used to let the card issuers set the maximum purchase amount allowed without pin/fingerprint.
Americans would probably complain if they were ever required to use a pin when paying with their credit card. Then they’d notice the difference because they have been using their cards without being asked for a pin all this time.
In my experience, either no issuers in the US allowed a limit to be set or Google explicitly only allowed it in Europe/explicitly disallowed it in the US. At minimum you have to unlock your phone with a PIN or fingerprint to be able to pay in the first place, with the terminal occasionally forcing you to do it again. At least with Apple Pay you're typically good to go once you use Touch or Face ID once.
As for PIN, I think people would have gotten over it eventually had it been made mandatory everywhere. Heck, EMV didn't get turned on everywhere at the same time and people got over that eventually.