Kishimoto fell into the trap of listening to the narutards who got mad at her character for being mean to Naruto and decided to sideline her. And then he couldn't commit to that and just had to have those "finally.caught up" moments in the final war, instead of letting her do her own thing.
Overall, her story arc is fine for a side character. A young brash girl who develops into a caring person, empathetic towards other. It's good development from all the shit she's gone through and how selfish she used to be as a child. Can't ask for much more.
My big issue had always been Kishi giving her the most raw potential in the Zabuza arc and then proceeding to limit her to the medical ninja. This bum of a teacher Kakashi, after seeing that Sakura was a raw genius in Chakra control decided to just have her walk around with him, instead of teaching her something to utilize her Chakra control into.