It also provides a shared experience that is an easy conversation starter when meeting sober later on "hey, thanks for last night! Where did you end up going after.." etc.
Obviously YMMW, in EU/Denmark it's a very common way to "crash course" people on each other when you suddenly find yourself in a new environment with nobody you know (university, new work). Then again, I'd say EU drinking is a lot more mature than the US one. We usually get introduced to it a lot earlier in life, and have a gentler intro curve rather than going from zero-100 real quick, when entering college or the likes.
"hours-long conversations over beers" sounds like getting wasted to me or at at very least tipsy.
It doesn't. But it can be, because - besides the "social grease" benefits it confers, which I mentioned before - why not?
Is drinking actually bonding though?