Let's be honest, Adrien could totally get away with not wearing a mask as Chat Noir. He is literally so good at Clark Kenting. Everyone knows that Adrien Agreste is a Good Boy who is too Famous and Busy for superheroics, while Chat Noir is a pun-master who lives and breathes chaotic energy and probably lives in the slums based on stereotypes. Heck, it seems like most people forget Chat has a secret identity, because so much of his apparent personality revolves entirely around his role as a Superhero. Ladybug having a secret identity is obvious, she brings it up a lot, and anyone can examine her behavior and go like "Ah yes this person is using an 'I'm in charge here' voice". But Chat's just, like, always there. And always acting like Chat Noir. No way Adrien can be him. Adrien's schedule is so busy he never has time for anything.
(It is particularly amusing that this logic also applies to Gabriel as Hawkmoth. Being overly dramatic the moment you get superpowers seems to run in the family)













