One has to wonder what will become of cancer if aging is ever cracked. I really think cancer is the reason life evolved to have age. Because then most cancers can age rapidly and die out early, before they've taken their host with them. We still get cancers, but I would guess we'd get a lot more without age, and not just because we'd live longer.

There are actually multiple forms of cancer that don't reactivate telomerase, and as a result age rapidly and die out on their own. Sometimes these are called pre-cancers, because they could still end up reactivating telomerase before they fully die, and then becoming a full cancer. A lot of them don't however, and a naïve solution to aging would remove this pre-cancer grace period entirely.