LUKE SKYWALKER - The difference between a Mary Sue & A well developed character is:  Struggle, change, failure, and acknowledging failure.

We, the audience, admire a character more, not for them being better than everyone else since the beginning (or trying once, then immediately mastering in seconds what should be a journey); But for how many times they failed, struggled, & changed to be the best in the end.

Another attempt, failure. (Good)

He is advised on what he isn't doing by a mentor, an established Master. (Important detail) Then he, the greenhorn, listens to the advice, adjusts, succeeds (AFTER failure): "acknowledgement of failure & thus change"

??????????????? ?? ???????, important. For how will the change, within context, feel organic if the character in question, isn't aware of why they should change.

Context is structure, without structure, chaos; Trash character.

Absolute domination by a Master opponent, fail. (Good)

Another instance, he manages to tag the opponent, provoking them to stop holding back, he loses a hand as a result; Loss, failure. He doesn't close his eyes, & magically muster up the power of plot, ???? ??????? ? ????? ?? ?????????? ?????? ????.

After some time, he, now a "Jedi", "Returns", AFTER training. NOW he can compete with his Master Opponent, even turn the tides, it makes sense. We've witnessed the failure, the acknowledgement of said failure, thus struggle, ergo change.

Now you'll reasonably point out: Technically, ?? ?????'? ???????? ???? ??? ?????????? ???? ? ????.
Yes, however, we've seen him train with 2 different people. Failing under both their tutelage, and succeeding after instruction in an instance, showing he has to learn, room to grow, develop.

By that formula & establishment, we can reasonably infer that he's worked for his current status, basic but important to plant these elements beforehand so the time-skip for said new abilities feels organic.

Precision & Speed.

Control.

Power.
And the best kind of power for a character, is learned power, earned power.

His evolution is organic, because he's struggled to achieve this level of Mastery. Luke Skywalker is a, classic, well developed character.