Amazon has always seethed about the Post Office because the PO has an enormous, indestructible competitive advantage in the shipping business: It knows everyone's address and the routes to them, which gives the PO ownership of "the last mile" to everyone's door. https://twitter.com/zachwritesstuff/status/1341552097939124224

While FedEx and Amazon can crisscross the country with planes and trucks, only the Post Office has the logistics and date for "the last mile" and that drives Bezos up the wall. It's why he keeps dreaming up drone delivery or whatever.

The last mile is Jeff Bezos' white whale and he will not rest until he destroys the Post Office's competitive advantage

https://www.retaildive.com/ex/mobilecommercedaily/taking-the-amazon-battle-to-last-mile-delivery-seriously

He's O B S E S S ED https://searchaws.techtarget.com/feature/Amazon-bets-big-on-last-mile-delivery-service-improvements

A fun lil power dynamic is that the Post Office could charge Amazon more for the last mile, and that would rip Bezos' profit margins into pieces of tiny little packing confetti

https://www.washingtonpost.com/business/2020/05/14/trump-postal-service-package-rates/

In conclusion, root for the Post Office every time. It drives the greediest people up the wall.