Luke using an illusion to save the rebellion was the best ending to the arc they established. He spends the whole movie angry that everyone is mythologising him and expecting him to be perfect. Then he uses his myth to trick the bad guys. If he’d showed up in person, he would have been giving in to the pressure to be this mythical figure. His arc would have been accepting that everyone who thinks Luke Skywalker is perfect is right. But instead, he uses the myth for shenanigans, which is a very much Luke-like thing to do.
Luke using an illusion to save the rebellion was the best ending to the arc they established. He spends the whole movie angry that everyone is mythologising him and expecting him to be perfect. Then he uses his myth to trick the bad guys. If he’d showed up in person, he would have been giving in to the pressure to be this mythical figure. His arc would have been accepting that everyone who thinks Luke Skywalker is perfect is right. But instead, he uses the myth for shenanigans, which is a very much Luke-like thing to do.