We're talking about video games, not Hollywood blockbusters. A fighting game isn't going to propel anyone to stardom. The Wonder Woman movie will probably help, but Ares is still incredibly obscure even after his appearance in the first Injustice.
My argument is about exposure. Before the Arkham series my brother had never even heard of Solomon Grundy. Then he became one of his favorite Injustice characters and now he's a fan. It's not about propelling to stardom, it's about introducing a character to an audience outside of comics. Many people became fans of Batman through a cartoon, people can become interested, aware, or fans of a character through a game.