What does it mean for workers to collectively own means of production? Am I supposed to own only the laboratory I work at or everything everywhere? What if I decide to change a place of employment? Why doesn't owning it though the intermediary of the state and your representative in the communist party qualify?
There's almost certainly going to be massive brain drain as engineers, doctors, and other highly technical fields completely staffed with labor aristocrats and the petit bourgeoisie flee your socialist paradise because of material interests and false class consciousness. Pretty much no leftist ideology have thought this far.