The USPS's unique financial burden is that they are forced by congress to pre-fund their pension obligations so they can't pull a Chicago, calculate things base

The USPS's unique financial burden is that they are forced by congress to pre-fund their pension obligations so they can't pull a Chicago, calculate things based on insane assumptions of returns and go "whoops we're bankrupt" at some unspecified date in the future as many a pension system has done. In literally any other context you would be cheering this on. Congress has done a lot of terrible things but the burden they have placed upon USPS isn't one of them.