The main reason it hasn’t been totally privatized already is that the country would fall apart without it. The USPS can deliver to unprofitable locations that the private sector would never cover. Even then, it still makes a profit naturally. Even though some ideologue Republicans want it totally privatized, enough of the GOP recognizes that they rely on the rural voters who vote by mail from unprofitable locations. If they get rid of Democracy, it might become privatized by dumbass fascists, but even then, the economy and federal government would unraveled as a result.