For us locally, the main problem with USPS, particularly in the past, is them
telling us the package is delivered when it most certainly wasn't. They usually delivered it a day or two later, so it wasn't a wrong address. This was especially bad when they were one of the contracted shippers for Amazon; I suspect they claimed the package was delivered so they could satisfy Amazon's 2-day delivery guarantee, even though it wasn't delivered. I'm guessing it became enough of a problem that Amazon stopped using USPS altogether.