Marx explained how the division of labor alienates people from what they produce, from the act of production itself, from their human nature, and from one another. People are forced to perform mind-numbing, degrading, or *harmful tasks* simply to earn the wages needed to stay alive, reducing human life to a commodity
Marx was also an adulterer and refused to take responsibility for children he fathered so I don't think he's the best person to listen to in this situation.