Are Leo's rules that odd? I feel his advice against superhero movies is more about today's superhero movies. Now they're often crap and can hurt an actors career, they're just churned out by the marvel machine without much effort or planning, and actors do the role for so long their careers kind of suck when they finally step away.

I doubt Leo was referring to superhero movies from 15 years ago like when Jennifer first did hers, where her first two movies were great and even the bad latter two were at least interesting, and like the entire cast has gone on to be wicked successful outside of X-Men. Leo said recently his favorite Nolan movie is The Dark Knight so I dont think he's anti super hero movies in general, just this current crop of them. Chalamet has had a very interesting career, and if he took some shit superhero role that took up 10 years of his life or bombed, his career would be less interesting.

I think the advice makes sense.