All life, literally all of it evolved and made progress due to survival of the fittest.
All life on this planet are hard wired to exploit loop holes and take advantage to get ahead.
Communism fundamentally cannot work because it doesn't incentivise someone to want to rise to the top to become the fittest instead the idea of communism is, be happy with where you are and do your best.
Well why should I do the best I cannot change my circumstances.
It is similar to cooperation strategies in game theory
There is no strategy better than
tit for tat when you have potentially malevolent actors (ie. someone who wants to take advantage).
Meaning the strategy of you do something then you get something else GTFO.
All other strategies they attempt to use for AIs fail dismally because trying to trust someone that can at any time decide to opt-out and abuse your generosity turns out worse.
Democracy and free market are the closest model to how nature behaves and thus the one that matches life's hard wired behaviours