Many people could become „wealthy” then, but their conscience prevented them from doing things that would be required from them in exchange.
If you want to draw a comparison - imagine that every single worker in US gets a personal „eject” button that gives them $1M to their bank account, but it requires them to do things that will be unethical and oppressive towards their friends, family and the population in general.
Kind of like joining a mob, but without the dangers that go with it.
Look at Musk. You think a communist country would tolerate a foreigner who became a billionaire and calls out politicians in a public forum? Maybe ask Jack Ma how his moderate comments were received.
I had an acquaintance from a communist country who was allowed to study in the US. One of the first ever. How did he get that privilege? His father was a high ranking party member who had a serious disagreement and was going to be expelled. The deal was “you quietly retire and we’ll let you son go to college in the US”. So he kept his mouth shut. They had total control, so using your family against you was fair game. I have no doubt Musk’s kid won’t face that same challenge.
Sure, both systems cater to the powerful, but one is a relatively open system and the other closed only to the “permanently privileged”.
And no, party membership is not guaranteed to make you rich. And membership is not easy to get.
(Disclaimer: my grandpa was a party member, he managed local part of the polish power grid.)