But Silicon Valley is where the talent is and is easiest to find. It's where growth is easier than anywhere else. The financial price is generally worth it.
As I understand it, most startups are founded wherever the founders happen to be. Once you have a concentration of talent in one spot, that's going to tend to be that wherever. It's rare to move away from the Valley to found a startup so you can move back later.
But Silicon Valley is where the talent is and is easiest to find. It's where growth is easier than anywhere else. The financial price is generally worth it.