The above answers why quality is a different parameter. You may choose a machine just because it provides better quality output, which is a totally different reason to prefer mechanization. If people prefer quality they might choose one over the other. I do not understand the causation you imply with west here. So labor became expansive => and manual work became dignified. How does that work? Which historical theory shows this causation? Half of europe has more than 20% youth unemployment, that should pretty much free up the labor and kill dignity for manual work.