There was no growth in Mags pretending to be good, then doing something bad to shake the twins confidence in him turning good. The I love you kids, but love mutants more and hate you father stuff can only go so far.
Her working her way through the Avengers ranks, becoming one of the most consistent members. Becoming a leader, co-leader, learning magic, honing that magic, taking on an apprentice, getting married, having kids. Numerous special moments with actual friends. Saving the world many times gave her actual progession. Hell having autonomy in stories even. That was growth.
Where here she's a beautiful corpse. Mocked, hated. No real friends, no real family. No other interpersonal relationships. Just a dry well of salt.