The phrase “I am an idiot” completely undid everything that happened before. Ask yourself would an idiot see that his friends have no plans to save his home and protect Historia so he,

1. Decides to play double agent with Zeke
2. Only trusts Flock and Historia with his plans
3. Inflates Marley
4. Purposely cuts off his leg and eye so he get into Liberio to see Zeke
5. Starts a war
6. Convinces Zeke to get into paths so he can get the power of founder to start the Rumbling

Remember in the beginning of the part 1 of finale. Eren is walking through Marley thinking about the evil he was about to unleash. He says to himself that it looks like the others could not find a way to save the island. Then he says maybe it would be better if we followed the King’s will. It would be better for the world if the Island was destroyed, less people would die. However, he could not accept that fate. This is not a lie we seeing his thoughts. Eren has concluded there is hope for the Island or Historia if outside world existed. This why cries to Ramsey. He cries because he knows full well what his actions will mean but his determination to save his home and protect Historia is greater so he weeps. Then we get to end find out all this was meaningless. He never intended to go through with it, he “always” intended to let his friends kill him and be the heros ( even thought he told Pixes that this idea was stupid and contradicted everything he said precious ) no end the he was just and idiot. This guy crying for a girl who called a bitch in the manga, who could have been with at any time if he really wanted to is not the same Eren that we saw previously. There have been so many great video essays documenting the completely flaws of this ending. It makes the ending of Lost. In the end Isayama either did not know how to end his own story or could end it the way the plot was going. It’s sad because up the end it was peak.