Economies of scale taper off: truly large concentrations of wealth are not needed for this, and oligopolies can free large companies from the kind of competitio

Economies of scale taper off: truly large concentrations of wealth are not needed for this, and oligopolies can free large companies from the kind of competition that drives the search for efficiency. I am not sure about how large concentrations of wealth are supposed to increase the standard of living across the population.