First, it’s a lot to ask of someone to leave the country where their friends and family live. Many aren’t interested in doing that.

Immigrating elsewhere is also not easy if you’re in a less in demand profession. Of course these are the ones where it’s most likely to have unsupportable amounts of debt.

If you’re a US citizen, you are still required to pay taxes on your global income no matter where you live in the world. If you ever get a tax refund, it can be garnished for federal student loans that are in default.