With artificial intelligence and automation the game has changed.
The ultra wealthy do not need massive amounts of slaves, they need highly intelligent people that can service/invent the new technologies.
Unskilled slave labor will no longer be critical, so who's seed will stay on the Earth?
Critical thinking tells us that a closed system will only support certain functions within its environment, in other words, how many humans can the Earth safely carry in a sustainable way?
Someone has told their view, see here: https://en.wikipedia.org/wiki/Georgia_GuidestonesGeorgia Guidestones
They have it at 500 million.
So, as it stand 93 out of 100 people would have to be wiped out. Think about that.
Would you like your kids to have a 7% chance of surviving, and if does survive a 100% chance to be a slave?