And this is not a perfect world never will be. Capitalism is the only system that gives true incentive. The rewards of socialism is power over others and few can have power so the rest share the misery.
I remember bygone days when loose talk trashed foreigners, the opposite sex, the other race and some other religions. Thats all unspeakable now so there is a vacuum that is being filled with hate for the rich. Once the rich become disenfranchized keeping out of the Gulags will become the new incentive.
Socialism combines an altruistic morality enforced by a centralized authority and enforces collectivism on the "have nots" who are not in power. There is no right to control one's person or property...the centralized authority owns and controls all of it. The bloody socialists (Stalin and Mao for example) permitted no exception from their iron-fisted control. Failure to comply resulted in execution. They each killed over 20 million people as they sought to force their brand of socialism over their respective countries. By definition an incentive rewards an individual for an accompishment. There can be no rewards when property ownership is restricted to the central authority. In the absence of rewards, there is no compelling reason to work more than is necessary to simply exist another day.
The Soviet Union figured out that a "pure" socialist approach could not work. They rewarded elite athletes and scientists with better homes, better food and other amenities. The Stalinist regime of North Korea keeps the military loyal by feeding them well while the balance of the country starves.
Zimbabwe is a current example of the rapid decay of a society under authoritarian socialist rule. The private property of the white farmers has been confiscated and handed to the cronies of the dictator Robert Mugabe. The whites comprised less than 1% of the population, yet their very specialized and productive farming techniques fed the nearly 13 million people of Zimbabwe and left enough to export. Mugabe has turned that specialized farming system on its ear. Small plots of land are doled out to his "war veterans". They do not own it and are on notice that failure to be productive will result in confiscation of the property. Further, they are told that they will be "rotated" to another property at some point in the near future whether they are successful or not. There is no incentive to improve the land and farm productively. The consequence is productivity that is so poor that it is below the level of subsistence farming. A nation will starve because the efficient farms that once provided food stand fallow.