What “socialist” countries are you talking about? The USSR? Because the USSR was a socialist dictatorship, not democratic socialism (more like Sweden). Also Marx talked about a true communism following capitalism, which is anarchic. Socialism necessarily depends on a government to distribute resources/ monopolize an industry.

I don’t think 100% socialism is a good thing. There are services like the fire department, though, that function much better as an entity of the state. Go look up what happened when New York gangs ran fire departments. Spoiler: they fought with each other while the city burned.