> Capitalism is the most successful economic system ever created and is responsible for more human happiness, prosperity and health than anything else.
Fun fact: "The initial use of the term "capitalism" in its modern sense is attributed to Louis Blanc in 1850 ("What I call 'capitalism' that is to say the appropriation of capital by some to the exclusion of others") and Pierre-Joseph Proudhon in 1861 ("Economic and social regime in which capital, the source of income, does not generally belong to those who make it work through their labor")" [0]
Both Blanc and Proudhon were socialists.
Further more, I would argue that kindness and sexual intercourse have been responsible for more human happiness than our current economic system, although it's possible that by "everything else" you meant "any other economic system", in which case maybe you would have a point, with the caveat that perhaps more primitive economies (your stereotypical 'merry band of hunter gatherers') would have, on average, healthier and happier inhabitants.
Or that 'socialist' Danes tend to be much happier than 'capitalist' Americans.
Or that with the regulatory capture of most industries by big company lobbying, our current economic system would more correctly be described as corporatism, where the means of production are owned not by individuals but by corporations.
And you could also argue that the North Korea/USSR were less happy than Western countries due to democratic, liberal governments being nicer than authoritarian ones.
^_^
[0] https://en.wikipedia.org/wiki/Capitalism