The core of Eren’s character is “freedom is my birthright.” This belief manifests itself in his “if you don’t fight, you can’t win” philosophy, because as a person born into this world, he’s free to fight against what oppresses him. It’s the driving force of his character throughout the entire story.
The reason Eren wants to see the ocean is because he can’t stand the idea that something is saying he can’t. Isayama has explained this.
interview link
Eren and Armin bonded over their dream of seeing the ocean because it represented hope to both of them—but their motivations were different.
Whereas Armin wanted to see the ocean for the sheer wonder of it, the first step in exploring a world better than the one they’d been confined to, Eren believed that if he saw the ocean, he was free—his fight against oppression would be over, he could see anything the world had to offer if he chose to do so. Anyone who saw those things would be the freest person in the world. The ocean scene is the end of this dream, the end of Eren’s idealism, and where his perspective diverges from Armin and Mikasa.
Does this mean EMA’s relationship is meaningless and no longer important to the story after chapter 90? Of course not. Part of the reason he activates the Rumbling is to save them. To prevent Paradis from being wiped out so the friends he loves can have long and happy lives. But it’s only part of the reason.
A big theme of the manga is being better than one’s father, and parents not passing their burdens onto their children. It’s clear that Eren absolutely does not want to sacrifice Historia. Not only because she’s another friend he loves, but also because he doesn’t want to continue the cycle of Titan inheritance—he doesn’t want to subject any more children to eating a parent like he had to, and he doesn’t want to leave the conflict with the outside world for a future generation to deal with when he has the power to change something now.
This is why it’d be a betrayal to the literal fundamentals of his character if an alternate reality existed that he eventually “sacrificed” because there’s no possibility he wanted that alternate reality in the first place. This is how I personally see Eren, and anyone is, of course, free to view him differently—that’s completely valid, but don’t talk down to, harass, or attack other people who disagree as if your interpretation is the definitively correct one and people aren’t allowed to say otherwise.
It’s never been shown in the manga that Eren secretly wished he could live out a peaceful life where he’d just be waiting for death—there’s never even been a hint at it—but we have been shown, multiple times, that he’s going to keep fighting back, he’s going keep moving forward to see what awaits him on the other side of this hell, no matter what obstacles try to stand in his way.
























