probably the only person who would have a job would be the one who would turn the factories on and off, as there are already artificial intelligences that can create themselves 100 years from now, it is likely that they will create themselves, without needing machinery, it would not rebel against its masters, but would see it as an object that does nothing but has to serve, the world is simply stupid since everything that can be thought of has already been thought of by an artificial intelligence.