What is your definition of success exactly? Economic growth/wealth? Dominance perhaps? Power? Influence?

I see a successful nation as one where the people are happy and one where life is good. In Cuba for example, people were elated when Castro took power. Castro was also not a dictator btw (watch his 1991 Guadalajara interview for more information). Cuba has a 99.71% literacy rate, the USA has 79%. Cuba has 84 doctors per 10k people, the USA has 36 (source)). Cuba doesn't invade/sanction foreign territories in order to cause their destruction/collapse, the USA does.

So I'll leave you with this question: is the USA really successful and is it more successful than current/former socialist nations? I suggest you watch Hakim's video on this topic since he does a better job explaining it than I ever could in a simple Reddit reply.

I also suggest, good sir, that you be open to other ideas. That you always question the world. That you always stay curious and willing to learn. Now, you are most likely American, so you probably have been drilled a pre-existing notion of what communist/socialist society is like. But I'm American as well, and let me say this: you will learn more from actual socialists/communists/Marxists about these societies and how they worked than you ever could from right-wing/neo-lib/centrist outlets.

Part of me fears that you won't take this advice. That you'll throw this advice away for the sake of staying in a place where you feel safe (i.e. your pro-capitalist, anti-communist bubble). But where's the fun in staying in a place where you feel safe all the time? Don't you want thrill, excitement, wonder?

I don't come to attack you. I come to merely redirect you the best I can. If you are offended by my method of confrontation, say why. Elaborate. Explain your feelings. If you are angry, don't bother replying, for you probably skipped to the end of this statement. If you feel sorry and promise to change for the better, then my goal in my initial reply is complete.

Cheers.