Earlier quoted context omitted.
Right, it's more that our society has decided that humans have no value until they're at least 18 (hell, with college degree requirements that age is approaching 22), so we have to store them somewhere until then.
Kids under 18 used to be valued as factory workers. Our society decided humans become more valuable when they are given the opportunity of a childhood filled with education instead of manual labor.
US student loan debt is somewhere around $1.4 trillion. For comparison, mortgage debt is somewhere around $8.9 trillion. That's a pretty damn big market. [0][1]
If that education was free, I'd wholly agree with you that it's simply our society deciding this is for the betterment of all. But when you combine these two sources of debt (student loans so we can get jobs that afford us home mortgages) then we're looking at a new, weird, first-world form of debt bondage. [2]
Again, I realize that's a very pessimistic point of view. Will be interesting to see how the history books view it in years to come.
[0]: https://en.wikipedia.org/wiki/Student_debt#/media/File:Stude... [1]: https://www.marketplace.org/2018/02/13/economy/divided-decad... [2]: https://en.wikipedia.org/wiki/Debt_bondage