It's required by law in New Jersey. It's just a happy convenience in New York. It's going to sound kind of ditzy, but I wasn't aware that people even pumped their own gas until a few years ago. It's just that expected here.
There's only one gas station around here where they pump gas for you, and it's in the middle of nowhere. Everywhere else, you have to do it yourself.
I'm the complete inverse; I had no idea that it was common for gas station attendants to pump gas for you these days.