If it wasn't necessary it wouldn't have been selected for, having nothing to do with the philosophical or spiritual significance. Those species that didn't age became extinct because their genetic pools were too slow and stagnant to adapt to environmental circumstances or non-adaptive altogether. Both of which are terminal at the species level. Evolution doesn't favor the survival of the fittest individual. It favors the continuation of life, generally.

That's been my concern; that solving mortality for individuals might be a death sentence for the species.