A slight addition to this topic. A lot of jobs also became software, even if your intention in signing up for the jobs was different to begin with. PCs were revolutionizing the world.
For about a decade I worked as an engineer in a field where the expectation (at least starting) was that metal gets cut, stuff gets built, and there's physical hardware.
Those existed. May have actually had more hardware interaction than many in engineering. Yet much of the day to day rapidly became computer simulations of the metal that might get cut someday.
In many fields, the organizational choice decrement on anything involving capital expenditure or purchase was so severe that usually the obvious choice was to run a computer model, and simulate what might occur. What else would you do?
Frankly a shame. Since there's a been a lot of development in mining technologies over the years.
Even for the folks that have an ecological focus, there's quite a few methods developed with limited degradation of the landscape, and reclamation of the mining sites into alternative uses (park, forestry, entertainment, tourism). The Wieliczka saltmine in Poland's an especially impressive example [1]
And these days, there's also a huge number of resources in terms of mineral identification and site mapping. The EMIT Imaging Spectrometer from NASA's a cool example that does remote satelite mineral identification from orbit. [2]
I'm only a little younger than Gates, and it seemed like, what else would you do? PCs were revolutionizing the world.