UPS and FedEx are cheaper and faster (for comparable services) than the USPS.
Unless you want to ship to somewhere UPS and FexEx don't deliver.
The USPS is required to deliver to all addresses.
The Post Office is in trouble mainly due to poor and overly restrictive oversight from Congress, which is limiting the USPS ability to respond to market forces (like limiting Saturday deliveries) and forcing the USPS to pre-fund its retirement fund 75 years into the future, in just 10 years: http://thegazette.com/2013/03/18/prefunding-care-is-real-postal-cost/
Beginning in 2007, the USPS has been required to pay 75 years of those costs in advance, and do so within just 10 years.
This pre-funding accounts for about 80 percent of the “losses” sustained by the Postal Service over the last six years. Indeed, that last quarterly profit was wiped out by a $1.4 billion pre-funding payment.
No other government agency or private company is required to pre-fund retiree health care.
No other company provides universal delivery service to every address in the country, six days a week. Even private shippers such as FedEx and UPS use the U.S. Mail for up to a third of their final deliveries to customers’ doors because they can’t match the efficiency of the postal network.
The rest of you assertions are just as flawed and/or incomplete, as others have pointed out. Medicare is vastly more cost-effective than private health insurance, with overhead expenses lower than any other insurer. It would be more so if it covered everyone.