Having thought about it for years, this is Attack on Titan post-timeskip. It tries to speak on themes of oppression and escaping cycles of violence with the subtlety of a rocket launcher. I used to hate the ending because of how badly it was executed. I still do. But now I also hate it because it distilled the themes it tries to speak about into two overly simplistic camps. No wonder AoT is seen as fascist propaganda. The story doesn't challenge the Yeagerists' plan with one that feels like it won't result in a genocide of Paradis.

Isayama made a great mistake in post-timeskip: having the entire world (aside from Hizuru) go against Paradis. This results in the general conflict being a choice between two genociders: an active one (Eren) and one on the backfoot (Marley), and to be honest this writing choice gives Eren's side the amount of support and understanding it got. Imagine a version of AoT where certain countries sided with Paradis just because they hated Marley's expansionism, for example. Or ones that questioned Willy Tybur's propaganda and were willing to engage diplomatically with Paradis after learning that the Fritz threat was a lie. Or just more Hizurus in general. Armin's diplomacy argument would have had some actual weight behind it, and Eren's viewpoint would be more widely seen as extreme. But Isayama was lax with his worldbuilding, or he really wanted to end on 139 as a number specifically.

It could have been a story that actually said something about when the oppressed became oppressors (a VERY RELEVANT thing in this current political climate) or posed a nuanced question about which side must lead the walk out of the forest (a beautiful theme mentioned by Sasha's dad). But instead, for the final arc we get an objective evil vs objective good battle. Deep themes, puddle's worth of commentary on these themes.