The USPS is no longer run by the government, though it is regulated by it. It went private years ago, and stopped being subsidized by the taxpayers. Has been in the proverbial handbasket ever since.... Employees are in two tiers, with newer hires (last several years) lower paid and with fewer benefits, except of course for the people in charge. The Post Office had a Postmaster General; the Postal Service has a whole group in his place.
Remember the Pony Express? It was done in by that newfangled telegraph, and then phones made that obsolete. Now landline phones are being pushed out by cell phones.
Without unions the rich would be richer and the poor poorer. I don't like paying those monthly dues, but the union has saved my job from unscrupulous bosses a couple times; in a non-union position I was "fired" because the boss decided to hire in my place her friend who needed more income but did not have the experience to get a better job on her own!
As for health care, when I got laid off recently my health plan ended too, unless I spend $600/month for COBRA extension of coverage, and even that would end in 18 months. That same situation is what made my sister ask to skip the usual Happy Birthday and instead have Happy Medicare as the sentiment on her 65th-birthday cake.