However it's dressed up slavery is slavery and a useful commandment from God himself would have been useful to God himself.Slavery has many nuances and it's not limited to the slavery of the 1700's in America.
Sometime biblical slavery is "indentured slavery'.....which has another context to it. There are those whop thunk every aspect of biblical slavery is the way it was in early America when the slaves were captured, delivered by boat, the people auctioned off then put to work.
In other words God's moral compass would be questioned less.
I'm not daft enough to think that slavery wouldn't exist, after all people break all of the commandments every day and always will.