From what I can tell, you are saying that not having slavery makes your games "less real." But that's nonsense, and if you can tell stories with gravitas and authenticity without including things like that, why do you need to include things like that?I'm on my phone and so finding it tricky to maneuver and make links to other posts that I'd like to so I'm only, for now, going to reply to this section of your post.
Your final point is - you can tell stories without slavery, which isn't much of a point. I can also tell stories with gravitas and authenticity without devils/demons or murder for that fact. Is that where you want to go? I'm not sure exactly what point you're making with that comment.
And by "you," I mean "companies that mass-produce books for an all-ages crowd," not you personally and your home table.