Municipalities trying to make their own Silicon... Alley, Beach, Hills, Slopes, Forest, Prairie, Bayou, Desert, Roundabout, Docks, Glen, Fen, Cape, Oasis, (and more!) with varying degrees of success, so I don't know that it is unreasonably replicatible. Despite all those efforts, OpenAI and Anthropic both are heavy hitters in the AI industry, and they are both headquartered in San Francisco.

Naturally, nothing lasts forever. Not Silicon Valley, not the USA, not the Holy Roman Empire. Some things do last quite a while though. If we look all the way back to Hewett-Packard, though now a shadow of its former self, it was established in 1939.