He does two things that increase believability: he cites papers and studies, and he runs experiments on himself. This is good.
He does one thing that decreases believability: he only cites papers and studies that reinforces his contrarian points, and benignly ignores the rest. This is called being a YouTube influencer.
In ML terms, his content has high precision and low recall -- he optimizes for true positives but not false negatives. It's a form of confirmation bias. You can still use his data (which I assume to be correctly sourced), but you might want to be skeptical of his conclusions by seeking your own disconfirming evidence.
Show us, then. He cites his sources. The least you can do is do the same.
As aren't you (and i). And why should i listen to a random Hacker dude? Or a smoking doctor? Dou you think every GP is a nutritionist? And even then...