I'm pretty sure most/all the people who think that college gives you a unique social experience that you can't get elsewhere are just suffering from confirmation bias, and also perhaps want to justify why they spent so much money.

I went to a top-tier 4-year university, and did develop several life-long friendships, many of which have led to introductions to other people, which have further increased my social and professional circles. It'd be easy to say if I hadn't gone to college, I wouldn't have that now, and, well, that's actually true... but it's missing the point. I'd still be me, and I'd still have the same drive to meet people and take advantage of opportunities. My life would be different, certainly, but I doubt it'd be less socially fulfilling.

If you work in Silicon Valley you will make friends that will pull you from company to company. All of the companies I worked for in my career (except 1) I got a call from a friend.

The one exception was they knew about me even though I didn't know about them. Halfway through one of my interviews I realized that I knew the interviewer by reputation.