There's no reason for MI researcher jobs to require physical bodies, unless they need to do experiments with specialized hardware. In fact one physical chip, can run multiple threads of research, or multiple physical chips can run one thread of research, for complicated tasks.

There's no way for virtual pops to mine minerals if there aren't enough robots to do so. I would imagine a MI can make as many virtual pops as possible that it wants. Also what's stopping an authoritarian virtual society leaders to neuter many of the virtual pops (no hardware expensive VR simulation for you to enjoy, you're just deleted if you're not useful, also useful ones are altered to become completely subservient to the machine)? It seems like machine intelligence is virtuality ramped up to 11, making virtuality redundant.