You miss the point. Why should USPS today in modern world be allowed to compete against private, tax generating entities. I work hard, make great money, then see a quarter of it siphoned off. Some of that goes to support my direct competitor whom, based on what my customers tell me, I run circles around.
the Post Office is not something sacred that must remain forever. Like the steam engine, it had its time and place. Paper letter mail is going to become obsolete just as paper newspapers and land line telephones are dissaperaing. Seen any video stores or photo developing kiosks lately? Western Union telegram delivery?
Things change. Staple items of “The Good Old Days” are not necessarily going to be part of our world in the future.