First class postal rate to anywhere in the country is 46 cents. What other organization could or would do it for that? "Junk Mail" and other marketing mailings, including political mailings, helps cover the cost.
Shut down the USPS? Seriously? Check out what they do:
One Day in the Life of USPS... By the Numbers - Postal Facts
Is the service perfect all over America? No, but it's pretty good when you consider the volume
I have never had a significant problem with the postal workers or service in The Villages (Sanibel), including mail holds or delivery. Knocked on the back door many times to pick up a package and they always help. In fact, the workers at our postal station often bring packages directly to my door.