The newer "web 2.0" companies (and I mean, even Google and Amazon) opened shop in more affluent places
The "older" companies were manufacturers. Even places like Mountain View and San Jose were the working-class towns with HP factories and semiconductor plants. The concentration of engineering talent (HP/Intel/Apple/Atari) is what created the affluence, especially after manufacturing itself was outsourced globally.
The newer Web 2.0 companies don't make physical things; they make software. Their most critical infrastructure isn't a factory but a dense network of developers. They go to the Bay Area, Seattle, etc., because that's where the network is. For the parts of their business that don't require that network, like customer service, they locate in less expensive regions, just as PayPal did with Nebraska. They were even the second largest employer in Nebraska iirc.
But modern skilled workers know how risky it is to put down roots in a place where they only have a couple employment options. So companies struggle to attract talent to remote areas and end up needing to hire in places that already have an established pool of skilled labor, which is typically in the cities and more affluent areas of the state or country.
In this case, the lack of employment options means many of the engineers laid off by Intel will end up needing to uproot their families' lives and move to a new city or state to find a new employer who can to pay for their skills.
I remember the first time I was sent to the Bay Area for training. I was excited to see this City of Mountain View I'd heard so much about; to explore its city nightlife and enjoy the view of the mountain. My boss had to let me down gently :) "Mountain View in Europe would be called a village", he said.
I don’t know how quickly we’ll find the political will to break that since everyone who owns property in a city has a financial incentive to keep prices artificially high. Removing density restrictions helps by making redevelopment financially advantageous for individuals but the degree of uncertainty we have now is going to slow that down, too.
Plenty of large corporations have headquarters in suburbs (where the rich execs want mansions) but in a close enough commute to a major city where more of the employees want to live.
