Cuba, China, USSR all saw massive gains in just about every measurable metric post revolution because they adhere to the theory that says you have to work to actively suppress the worst urges of the ownership class, aka the people who destroyed the biosphere and possibly life on earth for short term gains. The liberal rely your probably already wanting to type is to whinge about how these systems still had their flaws, arent perfect utopias, are authoritarian (yes, against capital) etc, but at least they get results and aren't idealism, but actual application of a rigorous program.