I still have to depend on the USPS for some things and their Priority Mail, or When It Fits, It Ships, are not only competitively priced with Fedx and UPS it's as reliably on time except for extreme weather interruptions that impact everyone.
If you sell on Ebay, there a lot of people who prefer USPS deliveries for whatever reason.
As for Saturday delivery, I thought it was already gone.
Yeah, the USPS. isnt the best government system but its in the Constitution and it would take an Amendment to eliminate it. Never going to happen.