Tbh they can showcase Storm’s Omega Level weather manipulation by giving her a solo and potentially a cosmic level threat to go up against. (And I know she’s defeated powerful opponents like Uovu and Adversary but I mean without the help of Stormbreaker or her Godhood. I want it to specifically be about her omega level weather manipulation) I do agree with what you’re saying though. Omega Level mutants have power levels that are undefinable and possibly limitless so if they wanted to they could effect the entire galaxy or universe. But X Office isn't gonna have the X-Men destroy the galaxy or universe. So they have to dim their powers down a bit.