First thing that comes to mind is friends father was hitting retirement age after working at a petrochemical/plastics facility for ~20 years, was in charge of maintenance of some section. I think he told me the owner had to call him twice to help diagnose problems that were causing product outages.

These things don't get built on a whim - there's risks, regulations, documentation, procedures, experts, etc. At the end of the day you have people doing the work for decades, with an intuition about how things work.

Given infinite time you can recreate anything - but by the time you're done putting the puzzle together you're out of business.