Your argument is predicated on the assumption that the rich use their wealth only for the "important forms" you mention. What you don't mention is how they are

Your argument is predicated on the assumption that the rich use their wealth only for the "important forms" you mention. What you don't mention is how they are able to influence the political arena with their wealth. The influence of politics by a few is a very natural consequence of massive inequality, and is a zero-sum game. More political influence of the wealthy means less political influence of the poor. You cannot divorce the economy from politics.