There's a thread about three years old on this topic, and I wanted to A) reply to some of those comments, and
B) offer some more recent observations of my own.
Many of the posters in that thread mentioned that FedEx Home drivers were paid by the delivery. This would explain why I've had FedEx Home delivering to wrong addresses and/or leaving several thousands of dollars' worth of parcels in plain view on a public street, rather than finding someone home and making sure the package got to the intended recipient.
Contacts with Federal Express in attempts to resolve that issue resulted in replies which stated basically "What issue?"
Whereas contacts with UPS result in the customer service folks moving heaven and hell in an attempt to locate the problem and correct it ASAP.
The postal Service is similar, although a bit more sluggish than UPS. Packages that go astray generally get located and delivery corrected if possible (with some notable exceptions - with the Postal Service, it seems to make a difference which destination post office the package goes through.)