Sailing and age brings on the physical pitfalls, some we can't do a thing about. But we have some new stuff today, joints, knee surgery(I'm looking into one of those,...), all of which I've seen extend the time people can deal with the general physical requirements of sailing. I see a lot of folks in their 70's still actively sailing around me. One such went to a power boat due to lack of agility. Then with a hip replacement, he's back on a sailboat, I think now in his 80s,
But I think there's also a mental side to it. Sometimes people feel less agile on a sailboat as they age, and feel an increased danger. Sometimes I see this in one partner of a couple.
My friends above have the typical ailments no doubt that come at their age, but they have a mental strength higher than many people their age. And their charter work keeps them active, that helps both the physical and mental I would bet.