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
The free market is an equilibrium that represents an average of all of our subjective needs, wants, and judgments. No individual will ever see all of its outcomes as ideal, but any attempt to 'correct' it will necessarily favor one person's values at the expense of someone else's.