He's smart enough to understand that while these interventions might help, they're realistically only going to add a decade or two to his life. And the stuff he's doing is fairly intensive – it's not like he's just changed his diet or something. Going to such extremes for an extra decade isn't affordable and likely not even worth it for most people who want to balance enjoyment with longevity.
I don't get the claim he's doing this for science either because even if he lives a couple of extra decades (say to 100) it would be difficult to claim that his interventions did anything at all given no trends can be made from a single data point. And the bulk of any longevity gains is probably going to come from simple interventions like exercise and diet.
So I think you have to be cynical... I think you have to assume he's taking an extreme approach to gain some notoriety within the growing anti-aging community and is trying to leverage that for self-promotion and profit.
I mean, why is he being so public about this stuff anyway? The guy has a YouTube channel where he talks about all the things he's trying so it's not like this is simply something he is personally interested in and occasionally writing about. He's clearly making his self-experimentation a business and clearly wants people to follow his journey. For example, this isn't simply information, this is marketing material likely designed to be shared on social media, https://freight.cargo.site/t/original/i/0128a596fea8b3a19e55...
I'm not hating though... I think it's kinda cool what he's doing honestly, but it's hard to not see this as a play for fame or clever marketing for a wellness / supplement business.