Not disagreeing, but Peter Attia likes to talk about healthspan. Most of us are fine with dying at 80. Most us will happily spend whatever we can to ensure the last half of our life doesn't suck. For me personally, in my 40s, (where I'm still at), I am in the best shape of my life, caridio-vascular-wise and strength wise, but recovery is a BITCH. I can do more pullups than ever. I workout nearly daily and eat really really well, even have gotten good about getting sleep, but the difference between me in my 40s vs 30s or 20s is I can barely get out of a chair after a good workout...for like a week. I used to be able to do much more and recover in a day, maybe 2 if I really fucked myself up...now it's several for modest workouts. I can't even run for more than a few minutes on concrete without knee pain the next day (but can bike 50 miles effortlessly) . I dread it getting worse...also the vision deterioration sucks badly.
So even if you make it 100, whatever you're doing to make you not feel like garbage will probably give you cancer...if life generally doesn't. I agree, I think we've hit our limit on total lifespan. Historically, we've always had people reach 100, even long ago, it was just much rarer.....so in my view, those genetically lucky outliers show the theoretical limit...what kills most, their system just wasn't impacted by, but none of them every made it to 120, 130, etc. The best we can hope for is more people to make to the age of those old folks in Japan.
However, there are also generic outliers who barely age...who are energetic and healthy and cognitively sharp into their later years...and it's not just the stuff we know about like diet and exercise...I've met a few who eat and exercise mediocrely...and known many who are supremely healthy and fit and age like shit. We should really figure out what is different about those genetic outliers. The economy would benefit MASSIVELY if we learned how to slow aging...as would everyone's quality of life. Imagine a 70yo being as sharp as a 40 yo and continuing to work if they wanted to? Imagine those over 60 being heathy enough they can be active and fit and die from car wrecks, stupidity (selfies near edge of cliff type stuff) or sudden cancer instead of slow, expensive, miserable deterioration? Aging makes us miserable, makes our total economy poorer, and completely sucks. While it is fundamentally a fact of life, like cancer, war, and disease....the more we can reduce it's impacts, the more society would benefit as a whole.
So to me, this is not the vanity project of weathly silicon valley types or Joe Rogan (who is really into this). They just have the means to pioneer something we all should be concerned about, but for some reason, place mild social stigma on. I personally believe there is a lot that can be done to ensure our later years and really all of our years are much healthier...and a lot of the techniques are not yet discovered.