If the median tenure is 3 years and the software business still is very profitable then people must be net useful within that 3 years. A lot of people also just don’t want to job hop much and honestly the interview culture keeps me from hopping more. I do still fall in the 3 years per hop but I’ve always had a good reason to- ie. layoffs, company going in a worse position than when I started, shit management at various levels, forever compounding responsibility…