Mining... for rare minerals...
this is the main objective for MARS. At certain point in time, we will run out of raw materials here on Earth. (not entirely run out but out of reach...)
of course manual labor may still be required...this future mining company may be the sole supplier of raw materials for future electronic parts on devices, vehicles, industrial or household etc.
The future will tells us that however advancement we achieved in science and technology, the limitation of required raw materials will always be the catch.