Shockley -> Fairchild -> Intel, AMD couldn't have happened with non-compete. So Silicon Valley couldn't have happened in Washington.

https://en.wikipedia.org/wiki/Traitorous_eight

Per capita isn't a good measure here, as Washington's weather helps lower the denominator (I say this as a former Seattle resident)

Seattles weather does nothing to lower the denominator. The PNW is rainy and somewhat cold, but not cold enough to kill homeless on the street in large numbers which is what folks seem to think lowers the denominator. And yes I do live in the PNW.

I can bet they happened with NDAs. Noncompete is another story, that is not the OPs problem here.