To my opinion, the reason that Captain Marvel thinks it is simple because from her mindset, she learned that her powers was from one of the infinity stone, and that her experiences in battle was just mainly winning due to those special powers. When she met up with the Avenger crew, she assumed that since they are superheros like her, she assumed they have some sort of powers that is similar to her. Gotta think about it, she barely knows him to understand what each are capable of and yet she think anything that crosses her path is easy.
RE: In the latest clip for Avengers: Endgame, why does Captain Marvel think its so simpl