I think this is too SV-centric (or even tech-centric). For instance, the major oil companies still offer pensions (and 401k's) and many employees stick around f

I think this is too SV-centric (or even tech-centric). For instance, the major oil companies still offer pensions (and 401k's) and many employees stick around for decades. They also higher senior management internally. Marissa Mayer figures are relatively rare in the industry.