It's simply a policy to honor existing student loan contracts. Trump-hole tried to make up the huge deficit his tax giveaways created by screwing over student loan borrowers. Biden has reversed that.
You see, most student loans over the last 20+ years were to be repaid at a variable schedule, based on the borrower's income. And those who made the scheduled payments were eligible to apply for partial forgiveness, based on their chosen profession. But Trump shut down the agency responsible for keeping track of that, so those who wanted to apply for loan forgiveness found that their payments hadn't been properly recorded or credited.
Only a fraudster and cheat like Trump--and the shitbags who worship him--would consider it a "cost" if you honor a contract--or would try to save money by cheating on a contract. The scumbags who LUVVVV Trump therefore have to claim that this is a giveaway. It's nothing of the kind. It's the federal government honoring its agreements.
Trump and Trumpers have no honor. Biden is an honorable man. That's the difference.