Nope. I just paid attention in school when it came to economics.
The Post Office set up the crappy business model. It's not Amazon's nor any other online retailer's fault and they shouldn't be punished or excoriated for taking advantage of the current business model the USPS has going.
Especially when it's the only profitable part of the postal system these days.
It's the same business model for shipping that Trump took advantage of with Trump Steaks
If Jeff Bezos was the CEO of any other online sales company Trump would still come after him and bash the company. In reality this has nothing to do with economics or the postal service.
Trumps rage isn't about Amazon...it's about Bezos and the crappy coverage Trump gets in the Washington Post.
I see a correlation here. For years the idiot left has been demonizing Walmart for (gasp!) offering lower (affordable) prices for their goods... with the accusation being they're putting "mom & pop shops" out of business. Well, if mom & pop shops charge more for their goods ... then perhaps the free market, working as it's supposed to, is what's putting them out of biz.... not Walmart.
Same thing here with Amazon. If Amazon can provide services cheaper than the propped up, ever-increasingly inefficient Post Office.... that's also a product of the free market... and Trump should stay the hell out of it with his petty tweet-wars crap. Amazon is doing nothing illegal, IOW.