Lol imagine having all that power and using it for gestures around at collapsing Empire

America has only been an empire for a short time as far as empires go. All countries built on Imperialism collapse eventually due to their inherent flaws (spreading too thin, overestimating their superiority, their actions being based on pseudoscientific "dog eat dog" philosophy) and the US is no different. If you want your society to survive you have to ditch the right-wing BS because that only creates a flash in the pan until one day you lose one too many battles as the people you crush get sick of your shit.

The only way to win in the long term is to not be an empire in the first place.

I'm not USAmerican, but from my knowledge, I think here are two reasons

1. Geographic location
   When EurAsia saw great destruction in the WW's they were far away and safe. So they could benefit from arms sales and similar stuff. Also got some experts and researchers fleeing from EurAsia, who helped in their development.
2. Decline of traditional colonialism opening opportunities for them
   Coups and takeover of places which where colonialism and other empires were in retreat.
   The power from the 1st point helped here.

Other stuff like the exploitation and murder of natives and slavery helped them set the base for these two points

well, first of all they basically immediately began plundering their entire continent. Then they stole a bunch of patented designs from the British, while being as far away from the british as possible, which allowed them to benefit from the industrial revolution with almost no reason to pay money to britain. Then, after industrializing, they turned themselves into the world's premiere factory, producing almost every kind of good, and being supplied by quasi-slave labour in every country south of Texas, as these countries were not being protected by a country that could have been a peer to the US. Then they took in a lot of europeans fleeing war and persecution, while said wars and persecutions were destroying the productive capacity of the rest of Europe (and after Europe had already destroyed most of the rest of the world's). Cut to 1945 and the advent of the Nuke, and now the US was holding the entire planet hostage.