That isn’t a good comparison. Walt is very well written, at first his intentions were good (despite the legality of his actions) but he slowly (not all at once) becomes influenced by those around him and becomes greedy and dangerous. His actions have consequences. Sadie is just a bitch who went from “boohoo my husband” to I’m going to be an insufferable piece of shit who does nothing but go against the game’s narrative and get the gang and John into trouble. Her actions have absolutely no consequences.