That's just never, ever going to happen. Never. No one would do the "dirty jobs" if there was no reward for doing so. Take law enforcement for example. Sure, everyone would "play detective" for free, or everyone would be the captain. But who would be the guys who ride in the motorcade to protect a child rapist while he rides to prison? No one would do it "for free". There's too much risk. Who would be a prison guard "for free"? It's absolutely asinine to think that "technology" will progress to a point at which humans are not needed for any menial/dirty/dangerous jobs ever.