The point is what is Eren's definition of 'not working'? Eren's first answer (well, pretty much his only answer) has been violence.
What?
Eren actively cooperated with the SC's attempts at diplomacy until he figured that the future he saw couldn't be changed. The reason why he's on the path to omnicide is because he figures that what he saw
had to have been the result of nobody being able to come up with a better solution to prevent the genocide of his community.
Even when he started the Liberio assault, he only moved once Willy declared war and called upon the world to join forces with them to annihilate Paradis.
His first answer wasn't violence. You'd have to oversimplify his character to come to that conclusion.
We still don't know what his real goals are except to keep fighting.
And you'd need to destroy their ability to fight one time.
You remember how Mikasa was still willing to fight with a broken blade and no gas with a Titan bearing on her during the Trost arc before Eren stone colds it? Or how Mike was still willing to fight against the
Beast Titan and his servants despite the fact that he had no means of maneuvering and he was paralyzed from the waist down? Or, hell, you remember the
Eldian Restorationists, who kept sprouting up in spite of the fact that they had no real means of opposing Marley?
Yeah, somehow I don't think people in this world believe in the concept of giving up on fighting against their oppressors.
The idea that a world would unite after losing all their military power and resources in a scramble to retain their own regional power is again, a joke.
You know, unless they're convinced that there's an island full of literal demons that itself has no allies that poses an
existential threat to everyone else, equally. Oh, right,
and has an abundance of resources, itself.
You keep hyperfixating on the fact that they don't like these people because of their race, but you're completely missing the part where their fears, for all they know and have experienced, are completely justifiable because the power of the Titans is in fact a real danger. You're proposing that alliances would be impossible, and you're also still advocating the killing of many--
even civilians (since you propose the destruction of capitals)
. Not to mention the other forms of hardship that would come from destroying several nations like how you propose.
Genocide's bad because you're killing a lot of people, including non-combatants, and you're also striving to inter their culture and history of existence with their bones, but all you're proposing in function is incompetent genocide that wouldn't work because the fear of the might of the Titans was the motivator behind the world rallying behind Marley to annihilate Paradis in the first place.
Then you know, don't make the main character become the fucking God of Causality
you keep saying that no matter how many times what you're referring to is broken down
I genuinely don't understand why people take this away from the series. To me it's an unabashed critique of all three of those things. It shows exactly how irrational, stupid and self-destructive the idea of blaming an entire culture for acts perpetuated hundreds of years ago is. It shows every fascist individual as a violent thug with no reasonable ideas of how to actually govern, and no coherent plan of action besides 'hit people I dislike till they shut up, then gloat how they made me hit them because they stupid or something'. It shows imperialism as leading to nothing but a hugely destructive cycle of violence that enriches nobody and creates traumatized, hideously scarred war veterans who are so psychologically damaged they're quite willing to kill the entire world or passively euthanize a whole species just to break the cycle and feel a tiny bit of peace for themselves.
Maybe
they think fascism, imperialism, and genocide is cool, and they're projecting.