My friend, you just suggested people actively want to be slaves. People don't want to be slaves any more than they want to be murdered or assaulted or addicted to alcohol or drugs - stuff happens in life, it doesn't mean you want it to. Slavery is a crime against humanity, not a career option.

Someone selling their child is not the child wanting to be a slave, and it scares me that you'd bring it up in this context.

Serfdom was close to slavery, yes, but involves a much more complex set of statuses (depending on country and era,) - largely speaking, serfs are classed (and banned) internationally as 'similar to' slavery, but the distinctions vary. Also, the ancient feudal structures of Europe are way too complex to go into in a comment.

Regardless, the original point I showed my disgust for was the portrayal of Black people as being naturally inclined to want to be slaves - which is both racist, and completely unconnected to Russian serfs.