Tbf, it didn't really pan out in teaching as there is an ongoing shortage of PGCE recruits and a massive attrition rate in the first few years. Michael Gove's attempts to reform teacher recruitment just made it worse.And in the police force.
Older, experienced officers - the ones who would have guided the young "think-they're-the-Sweeny" types on how to de-escalate situations, how to get to know the people on their patch, when to crack down on an offender and when to have a quiet word and move on - they saw the writing on the wall, grabbed their pensions and ran! And now we have entire forces of police who have two policing methods - "over-reacting" and "ignoring" - no nuance.
Most schools and colleges I have taught in had a staff largely aged over 40 for this reason.