They also have a number of competitive disadvantages, they have to pre-fund their pension plans, as well as the fact that they are required to service remote ad

They also have a number of competitive disadvantages, they have to pre-fund their pension plans, as well as the fact that they are required to service remote addresses that private companies don't, since they aren't profitable. And that's not even touching on the point that looking at the postal service as a private business is completely asinine. No one looks at the military or schools as a private business that needs to make a profit.