Number one fix in my mind.

Allow student loans to be eliminated by bankruptcy.

If loan agencies realize that giving out student loans to people who end up with worthless degrees and no job prospects who can't pay back the loan, and will eventually just declare bankruptcy to wipe the slate clean, it should naturally create a more generative incentive structure and make loaners more careful about who they loan to.

The inability to bankrupt your way out of student loans has perverted the entire system.

Alternatively, make college free (like many other countries) but increase the bar to actually get in and send the remainder to trade school.