Aging is natural the same way heart disease and cancer are natural. Some people get unlucky and develop cancer at a young age, but we don't throw up our hands and say whelp it's just nature.
We should treat aging the same way. Some people's bodies fail them at 80, but others live to be 100+. If we develop good treatments there's no reason that everyone can't live to be 100 in relatively good health.
> Aging is natural the same way heart disease and cancer are natural
How are heart disease and cancer not natural?
Aging is also slightly different in that it's how our bodies are supposed to work as far as I understand it, which is not very well (Possibly as a cancer prevention mechanism).
The parent isn't claiming that; they are pointing out that heart disease and cancer are just as natural as aging. We spend a lot of effort to cure heart disease and cancer, so why not do the same with aging?