This reads like "get rid of the old experienced people so I can get promoted".
If you are in a bad position then change, but if you like the company and role, don’t take it for granted and think carefully.
This advice is consistent with the broad statistic if more than half of the sample is currently in “bad position”.
Does anyone stay in the same position/team for more than two or three years even at the same company?
Given a fixed headcount, you can't have frequent promotions without either personnel turnover or allowing for employees to be routinely demoted.