I don't particularly like Lex or his style, but he's a brilliant guy, and probably the camera doesn't help him (in the past I happened to host a small TV show and you'd be surprised how much television "steals" from a person personality/enthusiasm/personality. I bet in person he's much less boring.
He's humble, he can listen and he actually can follow people in very nerdy paths of conversation. Not a superpower but a real skill. How many podcasters out there can really talk to Karpathy?
Also, he's not afraid to talk for a lot of time, even if the conversation appears to be boring. That is likely something that helps people connect with him (if you haven't, check out is interview with Rick Rubin). Intimate conversation take time and aren't really flashy. It's a different kind of Youtube, distant from the boombastic podcasters or interviewers out there, with dopamine cuts and tight editing.
It's like old school, serious stuff, and smart people like to be taken seriously.