In a fair capitalist system someone can be born in the lower class and come out on top. With communism everyone stays in the same place and the only people at the top are the top government officials. It always been like that in communist systems
Communism's survival, as formerly mentioned, relies on military force on civilians, or if human nature didn't exist to shift towards greed, envy, eventual ambition.
@Comrade Milsanki the collapse of the USSR that resulted in the formations of multiple ethnic groups finally getting independence from the predominantly Russian dominated government that suppressed their cultures.
Or Zimbabwe where mass starvation caused by the result of the deportation/murder of almost every white and forced collectivization of their farms lead to inadequacies and corruption and now more recently military intervention into the country
