What it is meaningless. is being compared to the guys in Zimbabwe since we will never go there. - being compared to the guys in Luxembourg since we would most likely just pass through.
It only matters in the circle that you are occupying. Often times those circles don't meet and we don't even know they exist. Even within the same country. Americans watched in dismay at the situation in New Orleans. No-one drives through Watts or Harlem. In my cushy suburban town I havenot seen any poor soul EVER.
With a few exception a billionaire lifestyle is foreign to folks on this board as much as a hobo life.
Close to where I live their is a $10-million home for sale but the property tax is in the $50k/yr range. You've got to sustain with super high maintenance cost. It might take a full month just to vacuum the carpet.
IMHO at each wealth level the key is to remain healthy and make sure you can sustain the burn rate.
Of course wealth disparity helps taking advantage of cheap goods from places like China and India but the standard of living is adjusting really fast due to trade imbalances. I would bet that 10 years from now goods from those countries won; t be cheap any longer and production will come back to the US. (It happened with Europe and Japan).