4) if everyone wasn't locked up in college, they would meet other young adults in their neighborhood and social/hobby clubs and entertainment venues

5) in the modern day that can solved by testing regimes. A self-educated quant could take an online qualifying test, and in-person final exam, to get a job in finance.

But tons of people aren’t locked up in college and aren’t meeting people in their area. They’ve also had their entire middle and high school years to do it. If they didn’t take advantage of it then, it’s unlikely they’ll take advantage of it at 18-21.

I think we are also forgetting that it is good for people to get out of their local bubble and get other perspectives/experiences.

I dropped out of college after 2 years about 20 years ago. I have never come across the same social interaction since then. The value of education on some degrees is certainly over stated , and there are areas that can be self taught. There is a lack of social learning though that doesn’t come outside of education and school.

In my experience - not really.

I know a lot of people around my age and only 1 person is working in my industry.

I disagree with your testing theory. The signal from a degree isn't just that you know the content, but that you can consistently work towards a goal over many years, navigating a large organization with lots of arbitrary rules, and willingness to do assigned work that may serve no purpose.

You can't test to show that ability.

4) is the main thing for 4 year, in person colleges, I think. You can learn anything online. Credentials are nice but you can get pretty good credentials doing 2 years at a community college and finishing up at a state university. But meeting a bunch of ambitious people your age at the same point in their career is pretty valuable I think. At least it is an opportunity to roll the dice on meeting your startup crew.

And just making friends in general. Most Jon's are not full of people the same age and interests

I know so many people who don't keep in contact with high school friends, but still meet up with college friends from time to time. There's just something special about throwing a bunch of people of the same age into this melting pot that they chose to be thrown in to that creates these social networks that last a lifetime. Military friendships also seem to mirror this same effect

Well, it's also typically the last place you get the opportunity to make a whole bunch of friendships before heading out into the adult world where it requires much more effort.