Referring to countries as "shithole countries" does not help in understanding the current dynamic between rich and poor nations. So perhaps it is helpful to understand what that is, without the pejoratives.
Firstly, each country is different. So the relationship between say the USA and Mexico is different to the relationship between the USA and say Ethiopia.
By "richness" we might also be better off thinking as less "spare cash" and more "standard of living". Which includes food, housing etc but also security, safety etc.
In truth much of the US "richness" depends on other nations. If there was no Latin labor the US would have a fresh produce problem. Indeed the very premise of DJT is that the US has a trade deficit with just about everyone. Much of US "richness" is thus dependent on the "poorness" of others.
Yes automation, cheaper energy, AI can reduce the labor content of goods and make them universally cheaper. Yes I believe in a future where the overall standard of living increases.
But it would be a mistake to believe the US is "leading" US there. The US achieved its current position at the barrel of a gun, and uses the military (and threat of military) to interfere with countries and regions either overtly or covertly. The entire premise of the cold war (outside of western europe) was premised on interventions to resist countries switching their political model to something the locals preferred.
And yes, maybe the locals preferred wrong. But the US didn't promote democracy, they promoted "willingness to keep supplying us". Countries which were leaning away from the US had to be punished. (Shah in Iran, Vietnam etc.)
I could go on, but I'll stop there. Suffice to say that an equitable standard of living is not in the (current) interest of most US citizens.