One's numerical age is the least relevent factor in determining a pilot's capacity to command an aircraft.
I've known of 20, 30, 40 and 50 year olds that should not be let loose near a serviceable aircraft.
Conversely, I've known of pilots of all ages, including 65 plus and 70 plus that I would let my family fly with, in any aircraft, any conditions. I also know of age 70 plus airline pilots who very competently and capably pass on their skills mentoring a younger generation of pilots.
Many of us decide to work beyond what society may think is a "normal" retirement age.
Subject to health and mental ability, the decision to continue working beyond age 65 is solely a matter of personal choice.