I don't drive, so me being drunk is not an issue.
However what is the point of drinking to the point you are drunk? Where is the fun in that? I got drunk because I has having fun and just had a couple too many. But people get drunk a lot and say it's "social" are nuts. I hardly ever drink and when I do it's a small party and normally a small amount.
I think "peer pressure" is one answer, even for adults. The last big social gathering I went to, everyone else at the party was actively encouraging me to drink more, despite my saying that my stomach wasn't feeling well and that I don't like to drink too much alcohol. But whenever I said these things they would treat me like I was a huge party pooper and I just needed to relax and have more fun. It was rather irritating. They kept pushing drinks on me and finally I just poured them out in secret to get them to stop bothering me. And these are my good friends!
I think that the reason this happens is that when people are getting drunk at a party, they want to know that everyone else at the party is drunk too, so that the next day nobody will remember the shameful things they did. But I remember!
I resisted because I did not want to drink that night, and usually I don't like having more than one or two drinks at all, but I can see how someone could easily give in to the pressure if people keep trying to convince them that they will have a better time if they keep drinking.