Capitalism makes labour into a commodity. This alienates workers from what they produce, from their work, from human identity, and from their fellow humans.
A classic description of Marxist alienation. And reading it I got a crystal clear sense of why the commodification of education happening in our universities today is so painful for academics. Both teaching and research are dependent upon human relationships, between teachers and students and between the researcher and the subject. Neither are activities that even have any meaning when abstracted into commodities and educational ‘products’. You basically cannot teach effectively if you are alienated from the curriculum you are teaching because it has been developed as a generic educational product. Good teachers are not simply educational workers delivering carefully priced units of education. The thing that makes good teachers, good is not the curriculum but the teacher themselves. A teacher alienated from their students and the curriculum by the capitalist commodification of their labour cannot by definition be a good teacher.