At 1-ish this afternoon, I got a text on my cell phone that my Amazon package was delivered. When I came home from Mom's, there it was sitting on the porch -- delivered by the USPS, not only on a Sunday, but on Easter Sunday. And I'm not a Prime member, nor did I pay extra for shipping; this was the "Spend $35 and it's free" shipping.
Meanwhile, FedEx and UPS don't work any weekends, at least not on home delivery (unless they farm out the last leg of the trip to, wait for it, the USPS).
I guess I'm one of the lucky ones that has little to no problem with the USPS. I do have the occasional issue when I put my mail on vacation hold and come back to find mail in the box because it took a day or two for the carrier to figure out that I really meant that I wanted the mail stopped because I wasn't going to be there to pick it up, but that's peanuts. I have had opened/emptied packages delivered to my house *cough* UPS *cough* and have have items broken in transit *cough* FedEx *cough*, but not via the USPS.