You are of course entitled to your opinion but I'd bet the reality is that upward mobility under Socialism/Communism is no different than that under Capitalism.I wrote this in another thread, but decided it needs it's own.
Poverty:
In Socialism/Communism, poverty is a state of existence at birth. You are either born in poverty, where you will stay. Or you are born among the elite, where you will stay. Examples of this fact, exist throughout history, all over the globe.
In a capitalist society, poverty is really two different states:
1) A temporary, escape-able condition (such as a business closure) or
2) A result of non participation in opportunities afforded to you.
Demarks ranks #1 in social mobility and they are much more socialist than the US is.