By vastly more complex problems, I think the parent is referring to engineering problems, not mathematical problems. And in this case quantity has a quality all its own. Yes, 1000 people in a bunker could in theory do the calculations necessary to refine airframes or planetary scale weather modeling, practically they would be impossible economically and would never be solved

We did get to the Moon on slide rules and human women calculators, and we haven't been back in person since.