What? Sano gets a ton of time in the manga and has a ton of fights himself. He gets Worfed a few times but mostly to set up the villains and it's usually somewhat conditional (he's injured or something like that).
Big One has a point, Naruto, DBZ, and Bleach are kind of outliers in regards to its characters. They literally sideline and make their cast useless or become jobbers for the popular ones or whatever crazy thing they have going on. In a lot of shonen fight manga and even seinen versions of them, the primary cast remains for much of it and are featured through the entire thing with their own fights and trials. Even if the main character is stronger than the rest of them, most of the team isn't that far behind in terms of skills and powers.