[stryan]

Practically speaking, USPS does a lot of last mile package delivery that no one else wants to do, including Amazon. If USPS wasn't delivering to those locations no one would be. And we're not talking middle-of-no-where-Wyoming locations, plenty of places east of the Mississippi have only USPS too.

There's all sorts of philosophical arguments as well: government services shouldn't need to turn a profit, all citizens need to be able to interact with the State and the post office provides a way to do that, mail-in voting, Post Offices can offer stuff like general delivery for those without permanent addresses, etc.

[SoftTalker]

There are lots of rural places the USPS doesn't deliver to. They require you to get your mail at a PO Box at the nearest post office, or have a mailbox at a common spot on the nearest public road (which might be a fair distance from your house).

[stryan]

They won't deliver to the house but they'll still deliver to that area. Amazon/etc wouldn't even deliver to the area without the infrastructure of the USPS.