How on earth do you justify this claim?
Also let us not forget other tools that have significantly helped capitalist nations: Slavery, Colonialism, Imperialism, Sanctions, Wars, Coup d'etat's... these have all contributed to what capitalism is today. So yes Capitalism in the grand scheme of things is entirely zero sum.
The data from the Fed show great inequality which can be expected from a zero-sum game. Another example check how under develop DR Congo is in the electronic age, while hardware (and to an extend software) companies are some of the most valuable companies, they all source raw materials from Congo.
Capitalism isn't zero sum because at its core principle are transactions, which are inherently non-zero-sum.