I appreciate representative casting, when the actors are good and their roles well written, but I don't think it "harms" anybody when a series neglects diverse casting unintentionally.
I have a friend who is black, and is a huge fan of geek media -- things like Star Trek, Star Wars, superheroes, etc. And one of the things he has often shared with me is how hurtful it was to only rarely see black heroes growing up, and to almost never see them depicted as the main characters. And he has shared how meaningful it has been for his daughter to grow up in an era where she gets to see a main black hero in Blank Panther, or a main female hero in Wonder Woman. When I went to see Wonder Woman with a female friend of mine, I noticed that she was crying during the "No Man's Land" action sequence. She told me she was crying because it was the first time she had seen "herself" depicted as the protagonist in a way that was just straightforward heroic (rather than, say, sexually exploitative).
This is not a personal attack, but you are just plain wrong when you say lack of representation does not harm people from marginalized communities. It creates lifelong emotional pain.