The US government doesn't have those billions lying around with no ideas about how to make money with it. It has to borrow it. Interest rates for US bonds aren't high at the moment, but they aren't zero, either.
And as others mentioned, these are the bad loans: those that people do not have and likely never will have the money to pay back or pay interest on.
Because of that, this is more a decision to do the government's accounting differently than a decision to spend money.
The US government doesn't have those billions lying around with no ideas about how to make money with it. It has to borrow it. Interest rates for US bonds aren't high at the moment, but they aren't zero, either.
And as others mentioned, these are the bad loans: those that people do not have and likely never will have the money to pay back or pay interest on.
Because of that, this is more a decision to do the government's accounting differently than a decision to spend money.