One of the favorite lines of the Progressive left is "Communism looks good on paper, but it has never been implemented correctly." It is my contention that Communism doesn't look good on paper either.
Wikipedia says "communism is the idea of a free society with no division or alienation, where mankind is free from oppression and scarcity. A communist society would have no governments, countries, or class divisions." So pure communism has no leaders, no elite, no upper class, no ruling class, no productive class, no dependent class. See where this gets a little tricky.
The Bible says clearly, "the poor you will have with you always," why? There will always be a dependent class, whether it is children or elderly retirees, the handicapped, or in-firmed, there will always be those people who do not produce anything. This is inevitable, you may be able to get rid of the less productive in a society simply by withholding their basic necessities, or killing them; but a society will never be able to get rid of the children, for obvious reasons.
And a dependent class will always take more than it produces. Obviously the women who are bearing the children will also be considered dependent at least for a short period of time. There are also those who are too old to work anymore, or those who have been injured while working or the insane or criminals. The list goes on and on of the dependent class.
Communism cannot ever be implemented correctly because it doesn't take into account human nature. Since Communism has at its core no government, pure communism outlaws a ruling class. But with such a huge dependent class, there is a need for some to rise to a position of decision making. Whether those who seek power do it for the better good or not, we know that "power corrupts". So any of the current communists claiming that they will simply give up all their power are simply lying to you. The myth of equality within communism is false.
The desire for power is only one aspect that it overlooks, there is also the means of production. This will take a little while to explain.
"From each according to his abilities, to each according to his needs." Karl Marx. Each person will have a certain amount of need, from the sick and infirmed to the healthy worker. Lets register that need as 10 bushels. To begin with everyone has a 10 bushel need. How that is produced is the contentious issue. Give a man his 10 bushels and he is happy to produce it, he will produce it for himself and his family happily for decades. For every person there is a 10 bushel need, so when the worker has additional children, there is an additional 10 bushel need for each, this means the man must produce an additional 10 bushels for each member of the family.
The whole system works great as long as the man is producing enough for his need and his families needs, but along come the dependent class and they need their 10 bushels each. Therefore the man's burden becomes greater than his need, because now he is producing for someone else's need. This is where the trouble starts. As long as the man can keep producing his 10 bushels and his families bushels all is well, but when he starts being encumbered with producing additional bushels for those who produce nothing, he becomes burdened. Now he starts feeling resentment for those who produce nothing but still get 10 bushels; remember human nature, you can tell him he shouldn't feel that way, but he still will.
So the usual response is, over time, to decrease his production level. The man will naturally decrease to a production level of feeding his own family again. There is no incentive in the communist system to overcome this. Forcing workers to produce only produces less, and appealing to their sense of "fairness" only makes them realize how unfair it is to have to produce more than his need for someone who produces less than their own need. There is no accounting for this basic human nature in the whole philosophy of communism.
In fact, scarcity is the direct outcome of communism, so despite their belief in a lack of scarcity, scarcity is one of the myths of communism. And from the above example, human nature takes over and produces alienation and division as another side-effect of the system itself. No matter how pretty a writer makes it sound, all it takes is human sin to step in and the whole thing is mucked up. For this reason alone, Communism is a flawed system that will always fail no matter who implements it. It looks horrible on paper.