Its not really a matter of practicality. Right now with todays amazing productive capacity a socialist society could exist - it could at any time.All it needs is the genuine enthusiastic will of the overwhelming majority to keep 'going the extra mile' as far as innovation, effort, organisation and commitment required of such production.
It requires the will to enthusiastically pursue the goal of 'from each according to their ability to each according to their need'.
It for those reasons, rather than reasons of pragmatism, that socialism is not happening, does not look likely too - and has a history of failure in economic terms, and often in moral and fatal terms.
