Earlier quoted context omitted.
Boston is the real deal when it comes to ID crackdowns. About 150k college students so some tens of thousands of fake IDs, plus a history of blue laws. I believe that legally they are even allowed to refuse legitimate out-of-state US drivers' licenses (most places do not do this, but they can). Foreign passports also can be refused. And that's not even counting the notorious "box scanners" which, to my knowledge, are…
Meanwhile in the UK I have had many places accept my expired US license from a rural state most have not even heard of. Once at a supermarket, a cashier asked me for ID and I absent mindedly said "No thanks". He was satisfied with that answer, and I didn't realize what I had said until I had already left with my drinks in hand.
If you're 16+ you can drink beer, wine or cider with your meal if it's bought by an adult. And in that scenario it would be rare to be asked to prove you aren't 15