Payments have also been paused for 2 years with no interest. I can say personally I have left the money “sitting around”, because there is literally no reason to pay the loans when you can just invest (or otherwise let inflation devalue the debt) and pay later

If that were the case, there wouldn't be such a clamoring for debt relief. Fact is that student loan calculations already take into account the assets of parents. Schools routinely factor in the help they could give into the total cost, and offer a package of grants and loans to make up the difference. If parents are withholding support it likely means the student can't meet tuition with their aid package.

it becomes a marginally rational choice to defer whatever you're able to though. even if it's only $500, that's $500 more in your pocket.