The CEO's of UPS and FEDEX state that it is network configurations and technological advancements that require the yearly 5%+ cost increases.
I was not arguing the merits or demerits of lost packages, but since you brought it up you need to take into account that each of the carriers have economy options that do not have guaranteed delivery and can- as you found on Reddit - have shipping movements that are perplexing.
If one were really to dig into that, you would find they are simply aggregating shipments and while it may seem ridiculous, one must understand shipping processes that are designed to save costs over direct routing. Think of it as, "well the truck goes there everyday and while in the wrong direction, we have a truck at its destination (a larger distribution center) that runs daily back to its final destination". Basically, its operations, and there is nothing odd about a package designed to be economically shipped going opposite of where it is meant to land.

