I think this game is much more openly recognized in SV without too much cynicism. The average tenure is probably around 3 years, and people move between companies often. This serves both the employee by diversifying their skillset, and it serves companies by facilitating knowledge transfer for certain techniques, particularly around scaling and operations for larger tech companies that individuals can't get through mere education or even small-scale work.

Consider that we openly talk about Bus Factor as a way of explicitly quantifying the indispensability of certain people; but the solution is not to get rid of them, it's just to train more people on those aspects. Of course there's still some amount of Machiavellian maneuvering, but at least while talent is thin on the ground employees still have enough leverage not to get screwed—not as badly as most non-unionized employees anyway.