As someone not an expert in capitalism but generally curious and knowledgable across a lot of subjects, my biggest skepticism of communism is that I don't see parallels to it anywhere in nature.
When I reflect on the patterns that seem to repeat across levels of abstractions (physics, chemistry, biology, psychology...) is there any example of a mechanism that evolved towards optimal that resembles (even roughly) the basic shape of communism?
I haven't found one yet, but if there were one I would expect it to show up in how cells in complex multi celled organisms (e.g. humans) organize themselves and manage resources. In other words, it someone can make a compelling case that a system in our bodies regulating our cells at large scales has strong parallels to communism, I'll be more inclined to think communism has a role in optimally regulating human behavior at scale. What I know is far far less than what I don't know, so it's possible there are many examples I just haven't come across yet.
Whereas I can see parallels to capitalism (free market competition and cooperation) all over nature.
Note I'm not making a moral argument here. I'm trying to use an understanding of the universe and nature to get an intuition of whether communism is a hallucination or an optimal algorithm, and if it is an optimal algorithm in which contexts is it optimal?