It's really strange how that worked out. Back in 1950, most people didn't go to college. Lots of people didn't even finish high school. If your employer wanted you to know shit, they would teach you on the job. I won't say what industry I work in, but most of the senior designers have no formal training. They just have tons of experience. They learned everything on the job.
We all assumed that teaching more people to be skilled would create a super strong economy where everyone is skilled, producing stuff, and contributing to a record high trade surplus. What happened next was shocking. As it turns out, and this seems obvious in hindsight, the demand for skilled labor is limited because the the demand for manufactured goods is partially limited by technology and the ability to find paying customers. There are a billion people in Africa we would like to sell refrigerators to, but they have no way of paying for them, so there's no reason to create refrigerators for them. It doesn't matter if we have 1000 factories or 100000 factories creating refrigerators - having more supply does not automatically increase sales. Supply side economics might work on a very small level, but diminishing returns is a real thing. 2 welders is better than 1 welder, but is 2 million welders better than 1 million welders? What if there is only enough demand for 100k welders? Diminishing returns. Adding more skilled labor does nothing to improve trade or productivity at that point, but it still has a cost associated with it.
And that's where we are today. We went all-in on supply side economics and it failed miserably. Instead of creating some magical utopia where millions of people can all be professional philosophers, we created an economy where millions of people hold a philosophy degree but work at Starbucks.