I wonder if what you're describing is that broad, or perhaps a slightly different phenomenon: A huge amount of the growth of SF's (the city proper) tech scene

I wonder if what you're describing is that broad, or perhaps a slightly different phenomenon: A huge amount of the growth of SF's (the city proper) tech scene seems to be driven by companies staffed primarily by very young (straight out of college, <30yrs) people. Similarly, much of the migration to the city seems to be driven by young folks (under 30/without family). Back in the old days (when I was growing up on the peninsula), one of the big reasons people wanted to live in Palo Alto/Mountain View/Cupertino was that they were family-friendly towns with good schools and communities. Companies sprung up on the peninsula for many reasons, but people at or near child-rearing ages (~30+) had their priorities set. I'm unconvinced that this rationale has changed in the intervening years. Gentrification and high demand have made living in the 'ideal' parts of the peninsula more difficult, but people still choose Palo Alto to start a family. Similarly, tech companies that tend to have slightly older workforces still prize their peninsula locations. Perhaps I'm wrong, but I think studying the demographics of SF growth may tell us more. That said, I don't think that the suburbs[1] are being marginalized at all. -- [1] While cities on the peninsula might be suburban in a way, they are quite different from suburbs in the rest of the country. It's a bit strange calling Mountain View a suburb when it is so different from a city like Needham (suburb of Boston) or the various suburbs of Seattle or Houston for example.