How does sacrificing America's lead make American oligarchs richer? That doesn't even make sense.

It does, it's textbook "banana republic". Dictator and close circles enrich themselves, everyone else gets poorer.

US voters were so worried that South America would come to them, that they have become the worst of South America.

basically make decisions that make no sense but benefit you financially. Sample. you run a printing business. you dont own it just run it. you sell your main printer and assign a performance bonus to your self. next month your business is closed because you dont have equipment to print, but you also have your bonus in pocket.

just like stock trader, you can get rich from going long, you also can get rich by shorting the economy (selling short).

this is what trump is doing: selling America short