Honestly, Ithink her leaving comes just at the right time.
Because there wasn't much more to do with these people: We had some scenes to show how MC is trying to cope with her situation and how others react to her powers. The school arc also gave a boss fight and showed that there are other players before stating it outright.
Plus we don't know if this is the last time we see these characters.
Or would anyone have wanted more chapters of MC protecting everyone, the kids idolizing her even more and the adults blaming her for everything? Because chances are that would have happened if she stayed.