My first salaried job (in 1957) was as a temporary, part time, mail man in a little farm community called Plano, TX. Then my first full time salaried job (starting at $2 an hour) was as a mail clerk in the Dallas, TX, post office for exactly 5 years (1959 to 1964). FedEx, UPS, etc. didn't exist. And I've always thought that poor management at the Post Office is what allowed those companies to take over the most profitable part of the mail service.
And now, many years later, I cannot understand why we still have 6 day a week mail delivery in residential areas. I can understand SOME (but actually very few) businesses needing 6 day a week service, but not residences and very few businesses.
When I retired from the police department in 1989, we closed on the sale of our house, and moved into a fifth-wheel travel trailer about 3 days later. We spent 6 years as full time RVers, visited at least some part of every state, except California and Hawaii, worked a few jobs in Anchorage, AK, and in at least 10 other states.
Now you might recall that this was all BEFORE we had our first cell phone or Internet service. I paid all bills with a hand written check and mailed to the recipient. And we used a mail forwarding service for a mailing address, and I'd call their toll free number and tell them where I wanted our mail sent (usually to general delivery in some town). And we had a "non-subscriber telephone credit card" that made using pay phones easy. So we NEVER got any mail more frequently than once a week. At my instructions our mail forwarding service disposed of all the junk mail instead of sending it on to us.
So I guess you can understand why I now receive mail 6 days a week, and wonder why the postal service is wasting their time and money.