If you're talking about US chattel slavery, your comparison is way off base and you should probably edit your post. Instead of firing an "underperforming" slave they could be legally murdered. Because all descendants were owned by the master indefinitely they could freely breed and rape "top performers" like animals in order to produce more slaves. When we end up with a corporate system that allows for that level of control of life or death in normal circumstances then maybe you can make your comparison. Institutionalized burn out is not it though.