The reason they posted a loss is because a 2006 bill mandates the USPS to fully fund all employee pensions 75 years in advance. There are full retirement accounts sitting around for employees that aren’t even born yet.
Even then, reliable postal service to all addresses in the country is a basic expectation of the government of the most powerful and wealthy nation in the history of human civilization.
The fact that you start with the premise that the USPS should somehow make profit off being a public service is a self report that you are here in bad faith.