I seriously cannot understand how anyone can defend Eren's actions with honesty, i can sympathise with his suffering however it seems that most you have forgotten what Gabi's character is for AoT, she is a reflection of Eren, she has the same motivations Eren had in season 1, but somehow they both have completely different ideologies despite having extremely similar upbringings and circumstances.
It's extremely obvious (considering how convenient that Gabi and Falco ended up at Sasha's orphanage) but Gabi is Isayama saying "war is bad, revenge is bad, do not murder people that are innocent", there is a literal monologue about this between that orphan who Sasha saved and Gabi, where it was clear that Isayama was portraying the main theme of this entire manga that people still misconstrued into something else. Eren has become the antagonist of the series because unlike Gabi, he is unable to understand the fact that killing people who are unrelated to his suffering is immoral, which i find extremely surprising because he has the ability to see the past and how his main cause of suffering are Eldians to begin with.
I still to this day, don't know why Eren does not see that his main cause of suffering is the entire existence of the Fritz family. The Fritz family are an altruistic royal family that forcefully brainwash people to continue suffering for the "sins" their ancestors committed. Eren's ultimate goal should've been to either, eat Historia and with his power show every Eldian the brainwashing that has been going on for hundreds of years. This is not helped by the fact that Eren also does not consider peacefully having a conversation with the rest of the world.
Which in my opinion Eren should've known that the ultimate goal would be to peacefully trade and have a conversation with Marley. As we see during the rumbling when people's preconceived ideologies of other races are tarnished as the world is about to end and they finally become humans, people are able to understand one another and reason with each other, knowing that people are facing their own demons and their own internal struggles, that we should be supporting people through hard times, not pushing them down. I really wish Isayama had made this theme more clearer for the retarded audience, but ideologies in themselves are anti human, ideologies force people to have preconceived ideas about other races, people, and things they've never interacted with before. God is the writing in this manga fucking garbage, Isayama has some fantastic philosophical ideas, he just needs to express them more clearly for the unwashed masses.