We also have to keep in mind that a lot of others would have died of unnatural causes like war. Scholars might be a good idea about how much of age expectancy is due to lifestyle compared with improvements in medicine.

They could tell ahead of time "This guy will live a long time; lets make them a scholar?" That seems doubtful.

Here are few factors that would enhance persons lifespan: access to clean water, shelter, nutrition, medicine, and not working in toxic or otherwise risky to your life environment.

yes, that is a survivorship bias.