Dan Luu

In the one case I personally saw, it was because the company is a great place to work. It's not like people are forced to stay!

People mostly left to change industries or move out of the city. IMO, making a place so great that people want to stay is good, not bad.

I agree, that if people stay, it implies it's a good place. But you can't have exponential growth for decades at many companies.

So 20-year tenure means not a lot of new hires, a static cohort, and not a lot of advancement for individuals--senior jobs rarely open up.

This is a sample size of 1 company, but Centaur had, by far, the most/easiest technical track upward mobility of any company I've worked for

There was no management track because there was basically only one manager (and ~100 employees), which was why some people left.

But on the technical track, I don't see why someone has to leave for someone else to get a raise/promotion/whatever.

Agreed, but even on tech track, ownership, responsibility, and influence are in limited supply; not everyone can be company-wide architect.