Your career is yours and yours alone, whether you want it to be or not. The sooner you own it, and take responsibility for all of the consequences of said ownership, the sooner you will find yourself creating your own safety from the corporate predators who pillage and destroy in service to the soulless legal fiction they call your master. Not their master, by the way. Yours.
A perspective worth considering, especially given the amount of Kool-Aid that gets passed around in SF/SV. Having a backup plan is pragmatic. Becoming indispensable is a whole other game, and one I feel is worth playing. Perhaps I'm naive.