Lex has a distinctive style of interviewing. He's intentionally laid back and talks slowly, and gives his guests lots of room to be the star. But he's actually a dynamic and interesting speaker and quite knowledgeable; you can tell by watching some of his lectures (he's an MIT professor). He dumbs down his questions to give opportunity to his guests to explain their topics in their own way and to appeal to a broader audience.

But having said all that, one youtube commenter said of Lex's interview with Elon Musk that it was "two robots conversing without human supervision," which Lex brought up in a later interview with Elon and thought was pretty funny.