>>715044551
The tradeoff is she fucking sucks at all of them and fighting because she grew up sheltered. She was afraid of a nonbender (initially) like Amon taking her bending. She lost battles to her own uncle and various other antagonists, Aang was a prodigy at two elements, Katara water, Zuko fire etc but Korra? She couldn't even do anything on the level of anyone in ATLA. Korra becoming the only Avatar is also treated as a tragedy, exemplified by her leaving the world as a wasteland in the upcoming sequel. Korra just sucks period at almost everything she does that in some twisted way /v/ should find that endearing.
You know another real Mary Sue type character is Miles Morales. I could go off on a tangent listing how everyone in Peter's character ensemble suddenly raves about the sheer radiance of Miles, but I'll use another one: he gets a fucking new power every other week. Energy projection, electricity, stronger than Peter, faster, more and more. And every one of his struggles just goes back to him not realizing how awesome and priviliged he is.