Well one component that has changed there is that the marginal tax rate on the inflation-equivalent of a Google Director pay back then was 80-90%, so there wasn't really a point in enticing people with large salaries.

Also, the factory workers you mentioned could afford houses in a big city on a single income. Now a single FAANG eng struggles to do the same unless they get N promotions, and even moreso if you tack childcare costs on top.