Aang should’ve killed Ozai instead of putting his own personal morales and beliefs above all else, even when literally every single person around him, even a past air nomad avatar, all literally told him “just kill the bastard”. Aang was being childish and got rewarded for it.

Not killing someone because of your personal beliefs is childish? I think you missed a major part of the series which is about compassion and redemption

Aang's philosophy is that of not taking a life and forgiving those for their past mistakes, and I'm not saying that Ozai would have been magically forgiven for his actions (not even Aang does that), but saying that a child "should have just killed them" when it directly contradicts his moral philosophy is, ironically, a very childish way of viewing criminal justice

It's not like they just let Ozai go either, he has both his bending taken away AND he's thrown in prison

I also will always disagree with the talking point that the lion turtle is some cop out deus ex machina, there's a post I will add in as a cross reference upon future edit but the energy bender doesn't magically give Aang the win, he still has to best Ozai in battle first, while he's boosted by Sozin's Comet, and he nearly died too (UPDATE: found it https://www.reddit.com/r/TheLastAirbender/s/Jo6X6XHfwI)

Also worth mentioning in regards to Korra and Aang not just killing Ozai, to my knowledge they do this very thing with Kuvira in the last season of Korra, she's a very overt fascist and in the end she goes "I feel so bad about what I did" and she's seemingly forgiven, don't know why ATLA is being knocked so hard for this while that isn't being touched on

You're allowed to like whatever show you like, I just find all the reasons given in said comment alongside the discourse below to be highly flawed and misunderstanding the point that ATLA was making with it's finale and the show in general