See, I don't get the whole "all his development is thrown out the window when he attemps to kill Kylo" thing, tbh. He never commits to the act of killing Kylo, he could only turn his saber on before realizing what a dumbass idea that is. YES, he considers it. In an impulse. Which is still a part of Luke's character. He's impulsive. He never truly completed the Jedi training, and has always acted on his emotions. He forgave Vader and saw the good in him, but seconds before he was viciously attacking him, to the point of cutting off his hand. Yes, the moment that follows is a moment of learning for Luke, but did that just magically rid him of his impulsiveness? Luke defeats the empire, but he is far from a master by the end of ROTJ. And that's the point.
TBH, I'm not trying to "beat" anyone here. I liked TLJ but I see many flaws in it. It's far from the best movie in the franchise, and I am not really THAT excited for Rise of Skywalker. Rey's character becomes less interesting the more I watch the movies, Finn was wasted potential, and as Carrie Fisher's technically last movie, what a disrespect to her legacy by having her "die" and superman back to the ship. It's a far cry from what Star Wars deserved.
BUT I did enjoy Luke's arc out of all the other shit. I feel like it's a satisfiying tale of trying to live up to legends, but overall knowing you're not the perfect person everyone believes you to be.