> Except in edge cases which might not really be capitalism
Oh well then those weren't real communism either. /s
You aren't wrong, but it's worth noting that the US protection of capitalism (more or less) was a pretty awful force throughout the 20th century.
Moreover, in its idealized form, capitalism has less of the state, whereas in its ideal form, marxism/communism has strong involvement of the state, versus classical socialism/anarchism in the Proudhon/Benjamin Tucker sense. There's even an essay by Tucker from the 19th century where he predicts the rise of leninism, gulags, venezuela-like conditions etc, as a natural consequence of Marxism, long before they even happen.
Otherwise, there are many contemporary examples of concentration of capital. Whether it is distributive isn't the question, but more the trends of distribution.
It's also quite interesting you mention central banks here, considering the substantial evidence of bulge bracket banks acting as an antithesis to your statement about risk (i.e "too big to fail").