It will look to the future exactly like emperors drinking mercury to extend their lives. I love it.
To put it another way, pre-civilization life expectancy was somewhere around 30 years. Would it have been wise to say to someone who was trying to live to 60, "So what? We all knew we're going to die from the age of five or so. This is pointless."
I agree that sometimes these health protocols are excessive, and can be driven by fear of death, among other things. It's also uncertain how many years on average any given habit will add, and there are opportunity costs that need to be factored in. At the same time, I see this common knee-jerk response to dismiss any attempt to extend human life. Given the abysmal state of health of the average person, I think it's a good thing that some people are working on figuring out what contributes to optimal health.
You probably mean life expectancy at birth. The birth and childhood were pretty tough, but if you lived to adulthood, life expectancy was just a bit smaller.
[1] https://en.wikipedia.org/wiki/Life_expectancy
[2] https://ourworldindata.org/grapher/life-expectancy-at-age-15
Go back 150 years and it was much more common.