I know what communism is. It's a philosophy of economic equality, internationalism, anarchy, and worker's self management. It is inherently a nice idea. However, it has historically either:
A. Caused a food shortage
B. Led to horrible dictatorships like those Stalin, Mao, Castro, the Kims, and even Lenin ran (this is, most of the time what happened)
C. Resulted in invasions partly due to a lack of a well trained militia
Additionally, collectivism cracks down on individualism, so such a society where everyone is the same would inherently "drop the hammer" on success and individuality because it needs everyone to be the same, and yet the community would need to do so, not the government, and when the government does it, we get something like the Soviet Union.