Wing Commander,
If you read my posts you would see that I don't believe we all descend into mental incompetence at 60yrs and 1 day. I'm nearly 60 myself but suggest there is a need to ensure older pilots are up to the job physically and mentally and not needing someone to hold their hand.
I know of 2 cases where older pilots used prescription medicines to lower their blood pressure prior to medicals, and on single pilot air transport ops tell me that's not a worry.
You fly with them.
P.S. The smart ones leaves the air force when they're Flt. Lts, not Wing Commanders.