Thanks! And I think your point is pretty well made. Because of how attitudes towards job change have developed over time from being negatively labeled a 'job hopper' to now having it accepted (and somewhat expected), older devs tend to have longer tenures in one place.
Now that even the youngest of the first dotcom engineers are probably hitting their 40s, it will be interesting to see whether ageism will still be a factor in hiring for the industry.