This is not why he gets these guests. Lex is very famous in his own right. His episodes on Joe Rogan's podcast are some of the most popular he's put out. He's a well respected researcher in his own right. Chris Lattner did not go on this podcast because Lex's dad is a physicist.

I think his affiliation with MIT probably helped to start with, but you still have to shoot your shot. He interviewed three billionaires before episode 20 (none of which would give a shit about plasma physics btw, lol).

Kyle Vogt and Elon Musk are explainable with MIT, being a researcher heavily involved with self driving. Schmidt, yeah dunno how he got him so early on. He seems pretty well connected in technology in general to be honest. Still has nothing to do with his dad.