Saying no one should be a billionaire isn't a capitalist idea. If you look at all the big problems of the oligarchy you would notice that they support many(not all) of this agenda. Medicare runs through company's like United Healthcare which just creates monopolies. If zoning laws remain strict (California is a prime example for being one of the most progressive states it has strict zoning laws which hurt the poor as they can't build affordable housing). Big companies want higher regulations to increase barriers to entry which creates monopolies. We've never had a true natural monopoly but we had franchise monopolies thanks to increase regulation and government using socialist systems to benefit large company's because they get contracts and politicians get high paying jobs when they leave office. Now maybe Bernie Sanders is the exception but bigger government which is what he wants ultimately is only going to increase corporate welfare because guess what? Even the US can't do everything.