One person having all the money and no one else having any money is a Pareto optimum. It's an equilibrium in a purely mathematical sense, but not the equilibrium we aim for as a society.

A change might come at the expense of one person, but can potentially help many more.

A 50.1% majority does seem to be what we use to decide things (with some edge cases meaning sometimes you need more , but rarely do you need less). One person, one vote and all that. Systems not perfect but it's a lot better than restricting to property owners