FWIW, your body can get better over time too! Aging can certainly make things more injury prone and such, but you can also be in good health and good shape even at an older age. Some things are affected by genetics, some of it’s environment, some diet, exercise, mental health, etc. It’s not a thing where you inevitably slide downhill and everything just gets worse over time. Far more complicated than that. If it were a simple downhill trajectory, then everybody who dies of natural causes would be dying at the same age.