I realize Google, Facebook, and Twitter are only examples here, but there are many more opportunities then just the “big name” tech companies. Your point stands: knowing how to write code is not always enough to get you a good job, and this will be more and more true going forward.

But I wouldn’t conflate this with the extreme scarcity of Silicon Valley jobs. There are tech companies most of us have never heard of hiring all around the world with salaries and benefits in between the heights of Silicon Valley and the lows of freelance. They may even be slower to be effected by the phenomenon you’re describing.