Yea human lifespan hasn’t really changed over time but as you say infant mortality, pandemics, war and a complete lack of industrial safety for over a century have skewed the average over the years.

I know plenty of people who are grandparents in their 30s today.

My country banned smoking in all public indoor spaces almost 20 years ago. As a smoker at the time I thought it was ridiculous, felt that my rights were being violated and thought it would never last. The quality of life improvement it made is massive. Today I vape rather than smoke but wouldn’t dream of doing either indoors or being where someone else is. It was 100% the right move. Not quite the same thing but you sometimes can’t really understand the benefits of an alternative to the status quo, even if you understand it logically.