For communism to work as intended past a tribal or perhaps city-state level, yeah, I’d say that we would need to be a different species. Communism works fantastically well when everyone is pretty closely connected; the larger a society gets, the less well it ends up working, without having draconian measures in place that largely eliminate all personal liberty.

I’m not saying that capitalism works well, unless you have a perverse definition of “well”. Capitalism does tend to give individuals some kind of incentive to work for what is nominally the greater good by creating the appearance that their own personal effort is tied to the results that they get. Conversely, communism, in large societies, has your input largely decoupled from what you get back. On a large scale, I think that democratic socialism will give the best overall results, but you have to ensure that no one has the ability to entirely fuck off and leech off the labor of everyone else without risking that infecting everyone, and resulting in nothing at all getting done.