Socialism is a material struggle, it isn't an idealist Utopia where everything is perfect. It's a process. And most socialist regimes have been in the developing world, which had much less to work with and much weaker infrastructure. Regardless, China has lifted nearly a billion people out of extreme poverty over the last 40 years. I also think that Cuba's accomplishments have been admirable, despite decades of aggression and embargo from the United States. You may compare these regimes unfavourably to a developed country, but that's an unfair comparison, because they weren't developed countries before socialists took over. Compare them to other, capitalist countries in the global south and I think there is no question what model works better