> But if the rich get 10X richer, and the poor get 2X richer, then everybody is better off.

If the rich get 10x richer, prices will rise by more than 2x, leaving everybody but the rich worse off.

These numbers are always given on a "real" basis, accounting for inflation.

Inflation is hard to measure because products get better and houses get bigger over time. But by every measure I've ever seen, purchasing power per hour worked has been going up exponentially or at least geometrically for 200 years now.

If you don't believe this, the World Bank, the IMF, and the US Federal Reserve publish reams of statistics about it.

People get turned around the axle of income disparity, because what actually has happened since WWII is that society has gone from being huddled pretty tightly around an average income ( a bell curve where almost every household made $65k) to a society where this has spread out further to the right ( a similar curve from $0 to $65k but now with a smushed peak a long drawn out tail going up into the 100's of thousands).

There are more wealthy families right now in the US than there has ever been. More people are earning more than ever before. But it creates a lot of societal fracture and strong negative perceptions. When the whole gang is broke, well we're in to together. When the gang ranges from broke, to comfortable, to some splurging, to wealthy, to flat out rich, the cohesion really takes a beating.

Wealth inequality is a good thing, but the cause of it matters. Was wealth inequality caused by theft and corruption, or by merit-based capitalism? If wealth is created and concentrated by capitalism, it doesn't cause social unrest.