I live near San Francisco, and rarely hear "Silicon Valley" anymore, "Bay Area Tech" has become far more common...so much going on now doesn't involve silicon and doesn't take place in the valley itself.
This region excels at accepting new ideas seen as ridiculous just about anywhere else. Some of those ideas might be bad, but there's a reason nearly 1/2 of all VC raised goes to Bay Area companies, and that's highly unlikely to change.
It's hard to imagine what will change 10-20 years from now just as it was hard to imagine how much time people would spend on something like Facebook ten years before it was created. Innovation is more than chance encounters, it's building up a company with an idea that seems absurd. No amount of serendipity would have gotten traditional NY bankers to back Facebook, Genentech, Apple, etc. And look at emerging fields like RNA sequencing, computational biology, ML, etc. You can't find the combination of brainpower and risk tolerance anywhere else.
The regional economy here once depended on gold mining, then on blue jeans and shipping, then on manufacturing, then on trade, then on finance, then on hardware, then on software, then on cloud-delivered software. It's remarkably adaptable and will keep exporting ideas - good, bad, and otherwise - that will get embraced by the rest of the world.