Jobs and the network effects happen all across the country. As you get older and maybe don't want the grind, or have a family, or just want a better work/life balance, this will become apparent.
Basically, always have at least two people who will support you for your next job.
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.