Someone should do the super duper hard work of figuring out what it was exactly that changed and made that stop working.

> has been dramatically more effective than America's late stage capitalism.

Depends on how you look at it, and which categories you measure, obviously? Why hasn't it caught on other than Nordic countries?

> Democratic socialism, also called social democracy, has been dramatically more effective than America's late stage capitalism.

> The heavily unionized capitalism that we had in the decades after WW2 also worked much better than our present system.

^^^ This. ^^^

What I'd really like to see is pick all the various bits and pieces from all the things that have been tried that do work well and try to build something around using those bits to build a solid foundation, using the mistakes of the past to learn from and avoid; not repeat ad-nauseam throughout history until it brings about our eventual end as a species. Clearly not gonna happen though. We're all too hell-bent on actively not seeing any sorta "big picture" future for humanity beyond "he who dies with the most money wins".