If a prospective student wants a degree that leads to a reasonably expected 1st year income of 70K, the lenders should not lend more than 70K total for the effort.
That way schools would tailor the COST of the degree program more closely to the return on investment.
IMO there is no problem with a 200K student loan for a Harvard Law student IF the graduate can reasonably expect to make 200K in their first year as a lawyer.
But IMO no degree should cost more than the expected income of the first year graduate. That means they can afford to pay it off in a reasonable amount of time.