I've thought about this a bunch
I don't necessarily want to live forever. But I am very curious about Humanity's ultimate fate. I want to see how things play out
I want to know if there is life out in the universe, if humanity ever meets other intelligent life, or even if we ever meaningfully leave Earth
I don't know. I love the good in humanity, I hope we eventually wind up more good than bad, and I just want to see.
Edit: Also, if we ever actually build a society that is a lot more meaningfully ethical and good than our current society, maybe I would want to live forever in it, or at least a very long time. Maybe it would just be nice to have the choice of when I go