I guess what you mean by communism is the fantasy that has yet to exist, despite concerted efforts by many well-planed and influential individuals and states.
We should not ignore the fact that in communism, you must have central control, or you cannot enforce it, and it becomes another system altogether, and rather quickly at that.

Just think about it, what if you were given a computer today, along with everyone else and told you had to mine doge into a specified account, but that doge would be used for public works. Would you mine doge? Or would you then mine something you could keep and resell for something else?

 The system fails because you would have to have tighter and tighter restrictions with brute force to keep people mining the doge in the way demanded. Almost instantly you are at a choice of totalitarianism or some other system like capitalism, and the hope of communism fails immediately.