(Pro 29:21 KJV) He that delicately bringeth up his servant from a child shall have him become his son at the length.
Is it “slave” (5650) (NASB) or “servant” (KJV)? Although it can mean either the most common translation in both is a variation of servant. In fact the KJV does not use it for slave. In modern culture there is a world of difference between the two, in the ancient world, not so much. The peasant farmer of ancient history had some rights but they were usually trumped by the nobility. Slaves had rights in theory also. Serfs in medieval Europe could not travel without permission of their lord.
Move down a little further in history and think of the place of the servant class in Victorian England. Picture the movie Mary Poppins is you can. The well to do banker had a house full of servants. He had lowly clerks at work. Everywhere he went his class made people pay homage to him. Of course he did the same for his betters.
This turned the tables in a way. It did not do away with the class structure but it said we have a responsibility to those “below” us.
So? Treat people well. You may not respect them but you are required to be courteous and kind.