A point I'd like to see discussed more, especially with people who are fans of capitalism:
Economic inequality makes money less useful.
My thinking: as inequality gets increasingly extreme, customer-facing vendors are increasingly motivated to price their offerings to appeal to the higher end of that range -- sacrificing quantity of sales for overall increase in profit.
The more this happens, the fewer people have enough discretionary spending money left over -- or, indeed, enough to live on.
Survival (and even prosperity) then becomes less about money and more about establishing supportive community (a mix of barter and localized socialism).
Take-away: #UBI is the only way to save #capitalism.