It's gotten very difficult to mail a letter these days. There are no mailboxes along my ten mile commute. Georgia Tech has contracted with an outside company to handle outgoing mail. To send a piece of mail requires filling out a form with an account number and many other universities have similar practices. Mail into or out of the university can tack on several days. I sent a piece of mail from Georgia Tech in Atlanta to the University of Pennsylvania in Philadelphia--two weeks from sender to recipient.
Why do I have to send mail in this world with email, texts and instant messages? Some places require "original receipts". Some government agencies require forms sent by mail or fax, and I've given up trying to find a reliable fax machine with someone who knows how to work it. It's still not always easy to transfer money to another person or company with a physical check. I stopped using the Netflix DVD service because it lost its value when I had to make a special trip to mail the DVD back. It's easier to find a Redbox than a mailbox.
Meanwhile most of the mail I receive is junk, or magazines, which look better on the iPad, or official letters that I have to scan to keep an electronic copy since they didn't email it to me. I do get the occasional birthday card or hand-written thank you note, a nice Southern tradition but we can live without it. USPS also does package delivery but that is often handled better by private provider such as UPS and FedEx.
So what if we just eliminated the US Postal System, say with a three-year warning? There is nothing that can't be replaced by electronic means and a planned closing would force the various government and businesses make that final push. We'll reminisce about mail like we did about the telegram. But why keep an inferior technology alive? It's time to move on.