Anyone don't want longevity for humans? I think death is a beautiful thing and for a lot of us including myself life has been really tough at times. The fact that there is an equalizer in death makes life comforting at times.
I think of it as, if my loved one (or me) were in the hospital with a fatal disease, but there was a cure, I would want the cure. I can't really see myself saying "Yeah, but death is so beautiful..."
I see aging the same way, as another fatal disease and I'd cure it if I could. I don't hope for an indefinite period of old age, but an indefinite period of good health, like 20-30s.
Where is the difference?
Life been tough, sure, but never at at any point did I think death is comforting, not even at the lowest point.
Not sure what the downvotes are about but problems of longevity is studied under vampire stories, e.g. Interview with the Vampire. They eventually get nihilistic and lost in ennui because they have lost connection with past and future generations and lost a lot, if not all, meaning in their life.
There is a school of psychotherapy (existential psychotherapy) that builds around death along with other existential problems (isolation, responsibility, meaning). A proper relationship with death seems to be meaning enhancing and anxiety alleviating than not, but it heavily clashes with other people who don't simply want to think about death.