There are plenty of tech hubs besides the Bay Area, that's for sure. But I can tell you that when I moved from a small company in a small economy to a moderately-well known startup in the Bay, the rate at which recruiters contacted me jumped from maybe a few times a year to multiple times per week. And after a few years, many of my coworkers started their own companies and invited me to join them.
By contrast, I have very talented friends who did not make the jump to work at a tech hub, and they don't have the same kind of network or opportunities.
With that said, I very much agree with you about wanting work life balance, making sure there are people who will support you in your next job, etc. However, I think that this is much easier to optimize for when you do have an established career and an extensive network already.
You've undeniably right about how there have been spheres of influence where people and capital come together. Every area of the United States has some kind of forced name of "Silicon *" for a reason.
I just don't think this will be true in the future. Move where you want to, maybe have to work harder to break through, but that was also true in the Valley.
By contrast, I have very talented friends who did not make the jump to work at a tech hub, and they don't have the same kind of network or opportunities.
With that said, I very much agree with you about wanting work life balance, making sure there are people who will support you in your next job, etc. However, I think that this is much easier to optimize for when you do have an established career and an extensive network already.