Conceptually there is no reason why Wanda couldn't have a meaningful role in the X-Men franchise, but the problem right now has nothing to do with her character and everything to do with the way that line is currently being run. It honestly feels like the entirety of the editorial, creative, and the fanbase never quite got over that brief period in the 90s and 00s when the X-Men were on top of the world, and are just obsessed with trying to replicate that success even though the overall landscape of pop culture has changed so much since then.