At the risk of dredging this all up again, Paul Atreides is fifteen in the novel, and most fifteen year olds look baby-faced. Chalamet looks the part. He's believable. And he's not a teeny bopper (unless he's been in a pop group I don't know about). He's had other excellent dramatic performances in the likes of Call Me By Your Name, Little Women, and Bones and All. He's a proper actor who deserves better than this kind of short shrift.

Also, I disagree with you re: Leonardo DiCaprio and Howard Hughes. I thought he was terrific in The Aviator.

That's my story and I'm sticking to it. :)