the inescapable fact remains, beyond the 60’s the odds of heart attack, stroke and other serious issues increase very steeply.
In Australia you can fly beyond 65 years (domestic) as long as you meet the (more) stringent medical requirements.
We don't seem to have many 'older' guys dieing or being incapacitated in flight.
If you want older pilots to GTF out of flying so you can take their place, well, that's quite selfish. Those guys earnt their stripes, and their experience.