I was expecting this to be about AI timelines or something. This is not very novel or interesting to me. Besides, it's not as if there's no plausible way to extend lifespans enough that I could live until 2123.
Individuals like Ray Kurzweil intentionally lied to themselves. His argument was that human life expectancy has been increasing rapidly over the past 'xx' years, and eventually it will accelerate to a rate such that life expectancy will increase by more than a year, per year - immortality. But it's just complete and utter nonsense. Life expectancy increased largely because of reductions in infant mortality - not people living longer. And he certainly knows that. Individuals like Hippocrates (of the Hippocratic Oath) lived to their 90s 2,400 years ago. The peaks of human longevity aren't changing much at all. The only thing that's changing is that more people are able to get to them.