I'm not saying it's an easy sell. The mood in the developed world is definitely protectionist.
It's not looking like a good deal to Joe and Jane.
At the time the US had a liberal business climate compared to other parts of the world. As a result a lot of industry was created and exported via culture.
What's happened since is that rest of the world caught up. Europe is no longer rebuilding. Soviet Union fell apart freeing a lot of nation states to purse western ideals. In Asian countries the regimes got softer and also liveried their economies. So there's a lot more competition. Globalization became possible and practical.
In the US life expectancy went up (medication and not smoking) so that made generous defined benefit programs a lot less practical. Women and African Americans can now do a lot of the jobs that were reserved for white middle class males.
All of these things contributed to white middle class American males losing out compare to what they had before. Baby boomers and before just happened to be in the right place / right time.
As the article speaks of half a billion people experiencing stagnation, that would make ~5 billion people experiencing double-digit growth.
I've heard the general claim of reduced poverty pretty often, but I'd be (genuinely) curious to see sources of it. It seems strange in light of the current migratory movements from "developing" into "developed" countries: As in, if poverty has been reduced by such a tremendous amount, why are so many people ready to risk their life to get to europe instead of taking part in the booming economy at home?
This is obviously false. When a poor country becomes developed, the net productive capacity of humanity increases.
The whole world is lifting itself into wealth, despite the hand-wringing of pessimists. It's awesome!
At the same time there are still more poor people than ever before in history, ~3 billion, so what is the net? 50 years ago there was only ~3 billion people on the planet.