IMO it's a feature. My reasoning takes into account mortality and reproduction (and is totally simplistic.) If there is no mortality but there is reproduction

IMO it's a feature. My reasoning takes into account mortality and reproduction (and is totally simplistic.) If there is no mortality but there is reproduction, we would soon reach a point where our environment wouldn't be able to support us (not enough resources). This could lead to a catastrophic collapse of the population. If there is no mortality and no reproduction, we, as a species, would lose our adaptability to changes in the environment. We would "stop evolving" and it would be a matter of time until we got extinct. If there is mortality and no reproduction, well... There would be only a single generation of individuals. This way, we can conclude that for "life", the best characteristics would be mortality and reproduction.