Kindly provide a single example of an alternative to capitalism that was in any way "successful" by metrics vaguely comparable to capitalistic success. No, you cannot point at China, their success over the past 5 decades was entirely a result of privatization and allowing market forces in their country.
Japan did not adopt a form of modern capitalism until the 1800s. The Byzantine empire was never capitalist. Ethiopia did not adopt modern capitalism until it was invaded by the west. Ancient Egypt was never a capitalist society.
> by metrics vaguely comparable to capitalistic success
If you measure by quality of life I'd say it's a dramatic loser.
If you unlearn decades of propaganda and realize the technological revolution was not created by simply stealing the value of labor from the worker and siphoning that up to the ruling class, and then combine that with the understanding that global trade controlled by massive banks created the capacity to destroy alternative economic systems, you might start to reveal the truth.
