The USPS is not allowed to decide what postal rates are. And the commission that is allowed to decide is prohibited by Congress from charging different rates for different destinations.
It is obvious that I am making a prescriptive argument. I am under no illusions that they are able to enact these policies tomorrow. Their hands are tied by regulations.
You know what might make those regulations go away? Making them hurt a little bit. If it becomes clear that USPS cannot exist as an institution in its current form without being a perpetual sinkhole in which to dump taxpayer dollars directly, then they will have no choice but to adapt or die.
...Or I guess we could just keep throwing money at them and hope they get better because they super duper double pinky swear promised this time.