The key, operative word here in your question is "supposed". Communism is a theoretical Utopia created by people like Marx of how they'd like the world to work, not how it does. It's easy to imagine a Utopia, it's totally another thing to achieve it. It ignore human nature in what happens when too many people get something for nothing, they stop working for it. Communism also has a complete shift in socioeconomics that people must be "actively managed" to conform to the new paradigm. Marxism is this transitional step. It includes total government and total control of the people. the people no longer own anything and some "benevolent" bureaucrat decides what they own, where they work, how they make money and how they socialize. Another attribute of human nature, power corrupts, takes over and stalls Communism in this Totalitarian State.
People under Communism wouldn't wait to get out from under it. Millions have died at the hand of their own government "for the good of the people". East Europeans think people are NUTS in wanting Communism or even big-government Socialism.
Socialism doesn't go as far a Communism. It entices people with the notion that government should "take care" of you. If one ignores the hopeless bureaucratic red-tape, poor service end economic waste, it works until it runs out of other peoples' money. This is why many countries are in deep debt right now.
Even China, who has had the most successful Communist regime, is moving away from it. Since the late 1970's, the more they have embraced Capitalism, the more prosperous they and their people have become. THIS is why they are the powerhouse economy they are now.