What roster is he talking about, because there are older characters than her who have been properly written without that baggage. For example, OG Thor, Cap and Iron Man have been consistently updated over the years and remain major characters. The current Avengers has obscure characters like Robbie Reyes and She-Hulk on it. Smasher and Cannonball were on Hickman's Avengers. This is about how she's written, not the character herself.
She needs a writer who's a fan of her's and wants to do something interesting with her. There are numerous characters in her position which have been modernised, without relying on that sort of angle.So Wanda's best hope of getting more relevance in the comics would be for a writer to do an Avengers team that is a throwback to the late '90s, which in turn was a huge throwback to the '70s. And I think Marvel is understandably skeptical about that approach because it would be so easy for it to be just pure nostalgia for old comics. (It's a tribute to Busiek and Brevoort that their run was not just pure nostalgia and stood on its own.) If they did a team with Wanda, Vision, Hank and Janet on it, I'd pre-order every issue, but there aren't all that many fans of old-school Avengers out there.