This has happened in the past: Robert Noyce leaving Fairchild systems to create Intel.
PBS made a very good documentary about the origin of SV: https://www.youtube.com/watch?v=LcOoQP7nhl4
Wikipedia's page on the subject has a lot of great information as well: https://en.wikipedia.org/wiki/Traitorous_eight
A short summary:
Noyce's exit from Fairchild changed everything. He moved away from East Coast control and a lack of ownership, instead pioneering the employee stock option. By giving engineers "skin in the game" (instead of just a salary), he fueled both innovation and loyalty.
This move sparked the "Fairchildren" effect. Talent left Fairchild to start dozens of new firms (like Intel and AMD). This fragmentation prevented a single monopoly from dominating the region. Noyce's model of flat hierarchies and shared wealth became the Silicon Valley blueprint, ensuring prosperity through a cycle of reinvested talent and capital.