@freemo Why no advantage?
Lots of poor people pose one clear problem for the economy: no money is spent, no process of actually creating value takes place.
Take some of the billions just lying there and invest in manufacturing the stuff we (humans) actually need. Not talking about taxing some middle class people that can hardly afford a nice house.
As far as i am informed, taxes for the actually rich (not middle class or just barely millionaire) are at an all time low. Why keep that up? If you'd say the rich will build eco friendly tech, you have already been proven wrong.
Lots of economic growth since money is spent, ecological improvement if scientists are in charge of what to build. Don't see why that would harm anyone, only good outcomes.