* Ability to drive places. Not worry about being "DUI" the same or next day.
* You'll exercise your ability to say no! In the UK for example it is sacrilegious to not drink unless you have a good excuse, which apart from religion (along with appropriate ethnicity to make that believable) there seems to be no acceptable excuse. So you can say "fuck you, I'm not drinking that shitty poison" and be an outcast for a while, then find people worth hanging out with.
Australia is not as bad because of the sport culture. "My personal trainer said no" is acceptable and most places I have work have had a mild to zero drink culture.
Not sure about the US, but I get the impression that like Australia and unlike UK, Russia, etc. it more acceptable to not drink.