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.