>>213685781
Chaos magic is tied to emotions, so you can make it so Wanda's powers depend on her emotional state, how determined or ambivalent she is (and she's almost always ambivalent), so, if you are a competent writer, it's not difficult to make her powers work narratively, and have her doubts limit her power.
However, if you are a lazy hack like Bendis or Waldron, you can just lazily have Wanda do whatever with no limits, randomly, with no coherent logic.