The fact that we have achieved a population life expectation that is at this number provides proof that this is the right number, or a least a lower limit to what the right number should be.   I wonder whether it might have been just an accident of history.   The high life expectation was a deviation from the normal value.   Perhaps it will be inevitable that we will revert to a much lower norm. 

This episode is also available as a blog post: http://hypothesis-discovery.com/2021/05/17/life-expectancy-as-a-priority/