Their Postal Workers Union runs the USPS.
Anytime you complain their first response is, "OK, then we'll just keep your mail at the post office then you have to come and pick it up"
We had a mail person with a real attitude. She used to delight in driving down the street gutter and throwing slush up onto a freshly shoveled sidewalk. The slush would freeze and couldn't do anything with it until next afternoon. She said she didn't have time to slow down.