> Both Soviet (and Chinese) parties in power were (and are) nominally "Communist", not "Socialist".
I have to disagree with this, especially given that the CPC claims that China is in the "primary stage" of socialism: https://en.wikipedia.org/wiki/Primary_stage_of_socialism. Communism in its original Marxist form is classless and stateless, which the PRC and the USSR certainly are/were not. Both countries were/are run by communist parties, but said communists recognise/d that a conversion from an agrarian, nominally capitalist society to a communist one would take a long time and require transition through a socialist state, as Marx originally laid out.
> My favorite example of communism implemented in real life is a hermit / monastic retreat, a skete.
The benefit to small communities is that it is easier to police for attitude and morality. Even more so if it's a religious community, though I'm sure Marx is rolling in his grave that you would call a religious community communist given communism's materialist philosophy.
> From the amount of hermits in a society you can estimate how popular this mindset might be, and how realistic is it to involve an entire population into it.
That's putting the cart before the horse somewhat. I know of many people who retreat from society in a hermit-like fashion for reasons other than asceticism or self-actualisation.
> Post-scarcity won't solve it, because it's not going to make people automatically care about the common good as a way of self-actualization.
But it will remove the primary need for an economy: effective distribution of scarce resources. It would also reduce the need for political hierarchy because property rights would become largely unnecessary to enforce.
> This is why the idealist Communist leaders of early Soviets spoke so much about "raising a new man", basically hoping to change the nature of humans.
They spoke about a lot of things that are purely based in ideology and do not gel with how the world works. Lysenkoism and the Four Pests Campaign strike me as good examples.