That’s not the prompt. He’s not talking about average wealth skewed by mega rich, but middle and lower deciles also being richer is what a richer society means.
Wealth by decile in poor society
100, 101, …, 109
Wealth by decile in rich society
101, 102, …, 1000000000000
This is what I was describing. Maybe I’m confused. What am I missing from the prompt?