I feel like high iq people are more likely to succeed in the USA, than a communist country. This comes from someone whos parents grew up and lived in a communist nation.
I think you are conflating relative meritocracy where the USA is better than some of the worst meritocracies from absolute meritocracy where IQ alone will help you succeed. There are tons of research articles (https://harvardlawreview.org/wp-content/uploads/2008/05/myth...) on the subject.
Some of the high IQ individuals are succeeding in USA but definitely not even close to all of them.
Some of the high IQ individuals are succeeding in USA but definitely not even close to all of them.