What may be a good mechanism for simple single-cellular, multi-cellular organisms, or even complex animals, is not necessarily a good mechanism for humans. If you’d like to argue that the omniscient deity intends humanity to die then perhaps that can be an acceptable philosophical argument. But evolution as a non-omniscient mechanism is not guaranteed to be an optimally benevolent process. There is no reason in that context to say that mortality is necessary for humanity other than negative emotions.