A factual answer from probably one of the few guys here who actually was in a fraternity in college.
The obvious answer is yes, fraternities provide a formalized clique where you and 15 to 50 or so of your drinking buddies and live in a house, throw parties, listen to Dave Mathews Band (or whoever the sort of kids who join fraternities listen to these days), bang sorority girls, not pick up after yourself and spend your college years relatively free from harassment from the administration on a day to day basis.
Of course, the relevancy of being in a fraternity largely depends on a number of factors, including the size type of school, popularity and number of Greek organizations, the quality of the fraternities and so on.
I went to a relatively small (few thousand students) prestigious private college in the middle of nowhere. Around 50% of all males students were in one of 35 fraternities by sophomore year. So for my particular college, there was a bit of a sense of everyone having to find some fraternity (or nowadays multicultural equivalent). If you were a wrestler, you joined the wrestler house. If you were a nerd, you joined a nerd house. Other houses attracted stoners, football players, soccer/lax players, rich jerks who just looked slick all day, Jersey guidos and what have you.
Interestingly, there actually is very little point to joining a fraternity at my college if all you want to do is party. Fraternities can charge for alcohol and they all throw parties about once a month which are open to anyone (translating to around 2-5 Animal House style parties every Friday or Saturday night). I suppose the main advantage is if you show up and act like a drunk asshole, the fraternity has 30 guys at their disposal. It’s also convenient if you meet a girl. Surprisingly, I found I was able to hook up with girls from time to time without raping them.
No, I’m not BFF with everyone I was in the fraternity with. But 20 years later many of us still get together from time to time. Then again, I also have work and high school friends I get together with 10-20 years later. One benefit that because we went to a good college, a lot of my fraternity brothers are executives, lawyers, investment bankers, hedge fund guys, Silicon Valley startup guys, management consultants, engineers and so on.
My wife’s college OTOH, the frat guys are all half-wit meatheads who mostly go on to be gym teachers or salesmen for some local company in Shitburg, USA 10 miles from where they grew up.