Why do the Vasari still utilize slavery when they make use of nanites? Slavery has only been used in our history when our technology is low-tech, with it falling into obsolescence as science and therefore technology grows, so why do the Vasari use enslaved lesser species as a workforce when they clearly have advanced technology?
Various forms of Sci-Fi will create tech that can indeed reduce labor but usually come at the cost of someone who has to operate it. Painfully lethal costs. A benevolent culture would try and minimize the suffering and only choose volunteers. A malevolent culture wouldn't care but would not want to use their own (except for punishment) and would use slaves of lesser beings to operate. Added bonus of not having to worry about the pain and once death occurs, replace with another. To bring in nanites into the picture, there may be certain nanites that enhance a being's ability to work and operate but forces the body to operate at extreme levels inducing pain and speeding up the death process. Vasari, being a rather malevolent, would prefer to use lesser beings to be injected with such nanites (the good ones that fix you up are for Vasari Citizens only) and put them to work.
A follow-up question: what would the Vasari civilians be doing when all the labor is done by slaves?
Perfecting the fine arts, science and technology development (and having a handy group of slaves around to do the nasty work), and other various activities that only the a higher being would delve into.
