There is a long tradition of show HN were the comments poo poo startups and ideas which end up being huge and the opposite is also true with praise and admiration of failures.
So with one data point ... For all we know, his Blueprint might be over-optimize for his own body and might be extremely detrimental to most people.
Although, on a side note, seeing how my grand parent fared towards the end of their life, I did realize that I do not fear death or aging, I fear the slow withering where you get more and more diminished. So I get where this idea is coming from
But on the other hand, I get a sense that the public side of his results are overblown. For example, my field is epigenetics, so I had a look at his "epigenetic clock" results. He uses "DunedinPACE" to track the rate of aging and his result is supposedly 0.72 (which very roughly estimates that he ages 0.72 years per a single astronomical year).
However, what is not mentioned, is that this result, while impressive, is not so extraordinary. He is number 6 in his own online leaderboard [1]. And the people who beat him at this metric don't do anything fancy to get better numbers than him [2]. Why not mention things like that along with all the optimism?
[1]: https://rejuvenationolympics.com/leaderboard/#absolute
[2]: https://fortune.com/well/2023/11/04/longevity-women-biohacke...
Also, I don't think the point is doing fancy things. The people that beat him might just be doing "common sense" healthy things. Something which most people don't do. See SAD (Standard American Diet).