The value of money comes from future economic output.

The majority of entities that will produce the most economic value in the future is the majority that matters.

In many cases, people who have accumulated a large amount of money in the present have done so because they have a high capacity to produce economic value and so in their case they contribute significantly to the economic majority.

This is not true in all cases, however. Someone who obtained large amounts of money through luck or via processes which are not repeatable in the future don't contribute as much to the economic majority as their current holdings would suggest.

This is the primary flaw behind who try to frame debates in terms of "rich" vs "poor". They aren't being sufficiently precise.