The real Marx intended that we should transcend the social conditions that require us to devote much worry to material things. With the increasing value of the world of things, proceeds, in direct proportion, the devaluation of the world of men. However, the real Marx and Engels proposed direct control of the workplace by the workers themselves, by some mixture of direct democracy and the use of elected representatives. However, since no society has ever really attempted to implement Marxism, it makes little sense to cite the failure of it. You might as well say that our last space mission to Alpha Centauri was a failure.
Nothing can be a failure if no one has ever tried it.