Medicine in its current form is just not prepared to deal with these things. It evolved to deal very well with infections and injuries, in both cases helping the body to heal itself, which it wants to do anyway.

Aging is different. An aging body actually wants to destroy itself. It intentionally disables self-repair mechanisms, allowing the diseases of old age to take over. It's the first time we have to override these internal goals. Treating these diseases individually, like we do now because it's the best we have to offer, is a losing game.