It’s not extinct when it is still alive. And what about all the organisms that live past their reproductive age, such as women who go through menopause, are they still organisms?
...they do tend to undergo some temporary retrograde primeval metamorphosis subdued only by chocolate, tears, rage and the blue pills when the reach that point...
We’re talking species here. Not individuals.
Most organisms reaching senescence do expire; they represent a resource sink within the population. In advanced animals, species that engage in forms of altruistic behavior are more likely to have individuals within the population of advanced age; elephants, certain birds, and of course humans, are known for this trait. The situation with humans is complicated by medical technology which allows for individuals to survive otherwise lethal events or conditions.