Depends what you mean by lost the use.
When the men in my family get to ~85, our bow leggedness is so fucked up that walking is painful and slow.
By by 60, I will probably get some if the tech is there, just I want to continue ranching until I die.
Discussion
i'm sure even better solutions will come along before then
both of my grandfathers died of heart attacks but they both made it to their 80s so i probably mainly need to take care of that
There is certainly a lot of nuance to it as with everything.
I guess it's the line of trying to restore normality after being poisoned or disabled by modern medicine, or trying to cheat the natural process of death or becoming superhuman.
I don't wanna cheat death, but I want to be as painfree as possible leading up to it. Backs and knees cause tons of pain in old age.