Previous editions of D&D have been deep, meaningful and have set out to teach important life lessons. This edition has no goal more lofty than being The Entertainer.
The variability of elven life-expectancy is one of the major causes for the human characterization of elves as being "chaotic." First they live to be 400 years, then they live to be 700 years? What does "average" even mean in such cases?
Worse, the elves don't receive any pay at all for changing their life-expectancy, yet they continue to do it anyway!