Brilliant analysis. I think that Ian McKewan's novel Machines Like Me, about a human-like robot who is treated as a thing by his owners, illustrates this idea exactly. It is all too easy to dehumanize those we see as merely useful. Black Mirror does a brilliant job with the mechanical dog episode, but even more so in the episode "White Christmas," where a woman enslaves a part of herself in order to have more leisure time. It's a brilliant allegory about how we hurt ourselves when we treat others in a transactional ways.