[AstralStorm]

Unfortunately free radical aging theories are not enough. It's a tiny piece of a picture, because effectively immortal organisms still use the same mechanisms. And it's not for some magic scavenging either.

Even telomere bound is not enough.

It's likely a set of advanced repair and local homeostasis so that feels still execute the complex maturing program correctly.

Too many senescent or damaged cells might just break the conditions... And mitochondria and cells have excellent mechanisms of dealing with reactive species they make, but sometimes chemicals leak in.

I'd be more concerned with infections and resulting damage at this point, plus toxic damage. Including endogenous like glycation.