Socialism was never given a fighting chance
Where it was attempted in isolation, for example in Allende’s Chile, among others, there were significant improvements in literacy, lowering of poverty levels and an increase in the participation in social governance.
However, these were anathema to the guardians of capitalism and so these progressive governments were all in turn replaced by US-sponsored dictatorships with generals trained at the School of the Americas in Georgia and economists trained by Milton Friedman at the Chicago School of Economics. The results were years of oppression with large-scale privatisation followed by mass unemployment and social breakdown.