Right, but oftentimes (but not always) the "cumulative damage" is causally linked to a single source. For example, when your kidneys fail, the rest of your body suffers crazy loads, since the kidneys are tasked with maintaining electrolytic balances in your blood, which other organs depend on. For example, failing kidneys don't clean out potassium from your bloodstream, which causes your heart to come under increased load and usually results in sudden cardiac death.
So replacing a failing kidney early on will keep your heart in a much better shape. Of course, in the long run, you'd need to replace everything, and in the very long run there's always cancer...