Don't quite remember where, but in the last week I came across a report of some archaeological work suggesting that rising sea levels around 3500 BCE (one of those little warmings I think) flooded the lower plains of the Tigris and Euphrates valleys, that area that today is the marshland of southern Iraq. And that the flooding herded people on to smaller patches of higher and drier ground, greatly increasing population density, and forcing people to cope by developing the first examples of government and infrastructure.

Conversely, the experience of America, starting as a few jumped-up colonies perched on the edge of a vast wilderness, showed lack of a boundary--the safety valve--lessened the desire for government. Until we filled up the continent, and natural and political boundaries started compressing the population. Then we started finding more government desirable and necessary. (Sure there's a political lesson there.) It's no coincidence that a lot of the people who today rail against government romanticize the Old West and the supposed freedom of cowboys on the open range (where they clivenbundied a living for "free").

Thomas Piketty, in "Wealth in the 21st Century", took note of the changing nature of wealth, that as you note, it depends less today on property, and a lot of it comes from the extremely high salaries of CEOs, entertainers, athlete-entertainers, and Wall Street paper shufflers. But there's a deadly catch: Without high inheritance tax rates, those high salaries get turned into dynastic wealth, which starts owning everything and creating a new aristocracy. All over again, because that's how it works. We always come to grief when we forget (or are persuaded to forget) how unrestrained capitalism works.