Most Americans with the means to travel also have access to credit cards with no foreign transaction fees and by selecting "pay in local currency" you get the best exchange rate.

There's still an ongoing trick that some European businesses do where they'll try and get you to pay in dollars because they can arbitrarily set the exchange rate. It's obviously within "reason" but on the higher end for no purpose other than to make extra money. I find such behavior to be dishonest and deplorable.