You are correct on the USPS making a wash, that is the idea at least. But on thing to consider is the ageing fleet that no one wants to deal with. https://www.uspsoig.gov/document/delivery-vehicle-fleet-replacement Most people do not give it second thought, but those mail trucks that deliver the daily mail are 25 years old. https://about.usps.com/news/statements/011516.htm Thats pretty old, when you consider they have 190k of them. Something is going to have to be done at some point.
As far as cheap goods pouring in, its an amazon problem. I am not sure if you saw, but amazon got nailed on a lawsuit about them a couple months ago. Basically it was a fly by night cheap chinese good company that made leashes, someone got their eye poked out with one and amazon does not keep enough records to know who the person should sue, so the court allowed them to sue amazon. As that becomes more common place amazon will either crack down, or just die by lawsuit, so that problem will be handled.
But granted, I will say, most of my clients don't have to deal with those issues because they manufacture their own products or have their own brands, so they have to deal with brand loyalty issues.