I believe the USPS can be likened to the army maintaining divisions of cavalry on horseback. It's long outlived its purpose...
Surprisingly, as someone who strives to go paperless, I actually like the USPS.
They deliver most of our Amazon packages. Whenever they get something in to the post office, they deliver it. They don't leave it sitting in a warehouse somewhere because the sender only paid for 5-day delivery. They're much cheaper than the big package delivery services. The folks at our local PO are pleasant. Before I buy a product on line, I look for a seller who has an option to ship via USPS.
And it's not just the junk mail but all of the inserts and other fluff which get included in the bills. Ever notice how fat the envelopes are which include bills or statements?
Some companies charge you extra for sending a paper bill or statement, then fill your mailbox with expensive, glossy pamphlets and brochures anyway.