It’s not just that liberalism distributed the wealth better. It actually turned the US into a middle-class country. As in most of history, the biggest class used to be the poor‒ about 40% of the country in 1900.
In the liberal period, poverty declined from 30% of the population to under 10%. Thus the idea that the US was a middle class country, one where the average person was doing well. This was almost unprecedented in history! The middle class had always been a minority.
Under plutocracy, efforts to reduce poverty ended. And now poverty is rising again; it’s up to 15%.