Worth pointing out the concept of "healthspan," which is pretty much like it sounds like: how long you stay healthy to do the things you want to do.
Long lifespan seems worthwhile if it's accompanied by a long healthspan as well.
It's definitely not going to work such that someone lives to 80 with a health of a 25-year-old and then something clicks and they start having age-related conditions, all of them at once for good measure.
Basically the odds of death don’t drop, you simply have 2 years vs 1 year at every stage of decline. Which means you end up with fewer people that are living to the equivalent of 70 as they had twice as many chances of dying before 70. And reaching the equivalent of 80 means surviving 20 years with the body of someone in their 70’s etc.
Thus the number of people living in nursing homes drops.
Another way of thinking about things, if you slow down physical aging to 1/10th, few people would live to reach a 650 year old retirement age unless you also reduce all other risks of death per year to 1/10th.
who wants to live to 150 is you’re in constant pain, take 150 medications/day and you cannot move?
now, let’s say that at 90s you could do what a 40yo can do. GAME CHANGING!