> post-WWII American boom years which were a fluke

No fluke. A deliberate policy

There's certainly some flukiness to being the only major country on the planet that hadn't been shelled and bombed to smithereens in the preceding decades. That's not the whole story, but it's certainly part of it.

We can't return to a place where America is the only manufacturing country in the world, where every other country is in ruins and rebuilding and taking loans from America. That was a very weird set of circumstances that gave America unprecedented tailwinds that no other country has ever had.