I really love this quest and Anduin character arc.
It's hard not to see the child in Anduin still, after this quest. It really makes it clear that he had to grow up far too fast (assumedly catalyzed by the death of his father in Legion).
And then there's what he says after the cinematic, if you click on him:
<Anduin looks curiously at his hand.>
I... I don't know what to think.
Just breathe?
Is that okay? I thought I had to find some answer... some great truth about myself in order to find peace again.
Maybe that's not possible. Maybe the only answer is to let it go.
Or maybe the great truth is that it is okay... to move on.
But how could I be allowed to move on, after the harm I've done?
These are all extremely realistic introspective questions one would ask themselves in his shoes (assuming one had the rather incredible level of emotional maturity and self-awareness that he possesses). The doubt is there, the self-defeating thoughts, the shame, the guilt, the self-punishment... all the things someone of his stature and background especially --that is, someone thrust into insane level of responsibility at a relatively young age as king of Stormwind and leader of the Alliance-- would probably feel.
His is just an incredibly realistic, really personable character with whom I can quite easily empathize.
I really love when Blizzard comes out with stellar writing like this. The people who don't care about the writing will probably just call Anduin "whiny" and say he just has "Light ED" (which I do find to be quite an amusing concept / analogy), but as someone who reads every quest in the game at least once, I really appreciate thoughtful writing like this! <3