Why not age 60 minimum for captains, with no deadline for retirement ?
There certainly is one
Honestly, even if you are still fit to fly at 70 - your chances of a sudden heart attack or a stroke rise exponentially with age, and I don't think we should accept the higher risk caused by that - it's like taking out a(nother) layer of swiss cheese
Btw: WCHC is no longer "Wheelchair Cabin" - it's now "Wheelchair Captain"