I'm going to firmly disagree and insist that no one should ever be a slave, and they are not meant to be slaves, regardless of their intellectual capacity or whether they were shown a good formula for life. Human society is in a failed state anywhere in which someone is forced into slavery.

I think you're committing a naturalistic fallacy, and I don't agree at all that people are ever meant to be slaves.

The most I can agree to is that "some humans are born into slavery due to chance". This is factual. That people are meant to be slaves is not a fact. Perhaps we have a language barrier here.