I think your logic makes sense, but in some cases may be wrong. The underlying assumption is that living longer personally will lead to a longer existence for y

I think your logic makes sense, but in some cases may be wrong. The underlying assumption is that living longer personally will lead to a longer existence for your descendants, which is probably true but not always. E.g. life extension may accelerate resource extraction to the point that your descendants die out sooner than they would have if you had died normally. Although you are living longer, your lineage isn’t. Also, I suspect that the cycle of life and death is like a computer reboot in that it is a reset of state. Leaving it too long without a reboot might cause existential level issues. Don’t get me wrong, I support life extension research, but I’m just skeptical of how ‘good’ it would actually be for society and the life extender themselves. Hopeful, but cautious.