Those that are cruel and savage, that are able to do what they need to do to live, are the ones that survive. That includes having the young push the old aside, even kill and eat them. Aging means that the strongest individuals in a population will not remain the strongest forever. Eventually, they will weaken and become prey to their predators. Similarly, the world's myths also feature countless stories in which heroes achieve transcendence through death.
Death is necessary for life.
Death revitilizes life. I don't, however. Moreover, I still see no evidence to change my view. In a universe where physical systems are constantly in a state of wearing down, and where organic biology exists only by indulging in enormous waste, death of individuals, an event that has absolutely no effect on the cosmos other than to provide the seeds for its localized revitilization, it is perfectly expected that biological organisms will wear out and die. I think the latter.