In a nutshell, it's the government's fault.

Democratic presidential candidates have been talking about the student loan crisis. And it is indeed a crisis. The total of the outstanding student loans in the US has more than doubled since 2009 when it was $675 million. The rate of delinquency on student loan debt pushed up to 9.5% in the first quarter of 2019, even as total student loan debt climbed to $1.49 trillion. Currently Americans owe more than $1.5 trillion in student loan debt. That's more than their outstanding credit card balances.

Democrats running for president have proposed government solutions, most involving forgiveness of most or all outstanding debt and making college "free."

The problem with this solution is it will actually make the problem they want to solve worse. Or actually, it will create a bigger problem than the problem that they're trying to solve. But the most ironic aspect of the whole thing is that the problem was created by government."

Before the government got involved, college wasn't all that expensive. It was government policy that made it unaffordable. And not only did it manage to dramatically drive up the cost of a college education, but it also succeeded in destroying the value of that degree.