This has little to do with socialism/capitalism and more with that fact that the economy was centrally (terribly) governed and most of the products were exported to the "friend nation USSR"
75% of sugar output exported to moscow and leningrad, you think the people of anywhere outside the immediate vicinity of those two cities got to see any of it? Let alone anywhere east of the Urals?
Ussr never fully recovered after ww2 and had to engage in a very expensive arms race while attempting to rebuild.
Imo saying that communism doesn't work often forgets this fact.
Completely different situations.
One country had to recover from complete devastation and bootstrap everything from scratch and fund and support allies with that.
While other European countries were barely touched it could benefit from US funding which was in itself completely untouched and benefited from the collapse of the entire capitalist competition worldwide.
Ussr provided major military assistance to china Korea, vietnam, African countries fighting for freedom.
Also look up comecon.
Also who do you think was responsible for reconstruction of half the germany? It was ussr most which was also half destroyed itself.
All of this was a much higher burden on ussr than US which was left intact.
I mean, they didn't have to engage in an arms race, any more than either side had to go to space or the moon. They did so for the propaganda, and to make themselves look tough, the same as the US.
They are in the same place where pro-capitalist liberals are when people talk about food insecurity in today's West, and let's face it, the rest of the non-Western world.