A few examples include the USSR, Cuba, PRC, etc. Life standards dramatically improved, life expectancy doubled in the USSR and PRC and jumped around half in Cuba, literacy rates jumped to 99%+ from less than 50% prior, education access, healthcare access, food access, housing access, all dramatically improved. Wealth inequality also fell down dramatically.
Here's an example of wealth inequality over time in Russia:

And how the Soviet Democratic process functioned:
