SE/SO has been on the decline for a long time now. They pivoted to find more ways to monetize the answers and started enshittifying, trying to appeal to business clients and money-people instead of the users and developers who built the knowledgebase. It was good when it felt like a community helping each other, it fell off when it felt like a company milking you to build out their monetized wiki.
At this point, from their perspective, the biggest fuck up was not locking down SE from scrapers and building their own AI. It is in every way the same situation that Reddit is in, just with a more focused and higher quality data set (and fewer, arguably "higher quality," users).
I agree with the analysis of the east coast, and will add that the South ("Silicon Bayou" is such a sad joke) is in basically the same place.
But I don't think the West coast actually has all those advantages either, not anymore. What passes for "innovation" is all some variation on crypto, ai, or "being the Uber of $NICHE." Throw in some buzzwords like IoT, quantum, blockchain, or "smart" and you're all set to race with the other founders to get a piece of that sweet sweet VC dollar.
The financiers have taken over everything and are going to drive the economy off a cliff so they can scavenge and sell the parts. They've taken over film, gaming, tech, all traditional media, journalism, and they're using the banner of "privatization" to finish off healthcare, education, postal services, and anything else they can convince idiots to sell them. The bankers are winning.