My take on this is that the US truly experienced a period of 'greatness' for around 40yrs, starting with FDR's response to the Great Depression in the mid-30's. Then you have post WW2, and the US was considered something of a hero nation around much of the world, plus was one of the few major countries with lots of intact production going on, with lots of demand around the world. For some decades there, you could work a job like gas station attendant and make a salary good enough to buy a home and support a family (I may be exaggerating somewhat, but the point's made).

Nothing is ever perfect, and of course you had various minorities getting the short end of the stick, or outright blatantly discriminated against, as with African and Native Americans. But for the larger populace, I understand that you really could live a pretty comfortable life, with social safety nets available if you were struggling.

Cue Jim Crow laws being struck down in the mid-60's and a huge hippie movement to relax norms and expand one's mind, and by the late 60's you had the furious right-wing, dog-whistling movement responding by electing Tricky Dick, and it's been a slow (but increasingly quick) return to the robber barons, blatant discrimination and the breakdown of democracy.

I'm not super well-read on all this, so might be missing some key points, but my take is that the USA as a whole has not remotely appreciated how good things were for ~40yrs, starting with most Boomers. It took the Muckrakers, two Roosevelts and the Great Depression to claw our way out of Monopolies and corporations taking over everything, and now we've lost most of that, and are hurtling towards 1984, even as civilisation itself is heading towards... a pretty rough ending.