If you mean creating artificial wealth for a small group of already-rich folk, yes, it works. If you mean transforming one of the most naturally advantaged landscapes on earth into a traffic-choked sea of concrete where people do little more than work at creating new ways to buy and sell stuff, yes, it works. If you mean polluting what was once the most democratic communications vehicle available with social drivel and advertising, it works.
If you mean creating innovations that truly improve humanity, the Valley extremely inefficient. If you mean demonstrating that humans don't need a pleasant natural environment to survive, the Valley is on the right track.
The one thing the Valley works very well at is self-congratulation, especially among the wealthy.