But this is less "listening to other people's opinions" and more "you should do this becase story themes demands it, don't be sad anymore".
Kouta doesn't resolve anything, he has someone else to do it for him. Specifically, the narrative.
You say that the story is rushing through the paces and is forcing its way to finish the plots. I feel differently, and I think the story spent just enough time on that particular plot point, and wrapped it up as much as is sufficient, while opening up other plot points. Really, the story, is far from over.
Talking about that scene, a part of the story there is that it is indeed "Sagara driving Kouta back into the fight, when he was about ready to drop out". It's not unreasonable to say that Sagara
was forcing a view on to Kouta, and gave him the tools to move forward with it. For his own ends and agenda, whether it be benevolent and malevolent. The music, and the atmosphere of the scene, was actually really grim and foreboding, all pointing to the fact that, in a way, the "upgrade" isn't really a good thing to happen. The story arc of Kouta's struggling with his dilemma may have ended, but it opened up questions and mysteries of Sagara's identity, his motives and end goal. And what that meant for Kouta and his fate.
And as a friend eloquently put, not liking people's extreme views seems less like a stance he’s taking than an indication that he’s a limp rag.
I can agree that not taking sides can mean that he does not have strong conviction, and the resolve to see them through. But seeing that said extreme views are 1)living in a world of lies and apathy of everything else other than your own interests, and 2)dooming a ridiculous amount of innocent lives for the survival of the few; I can sympathize with him being hesitant, assuming he has any ounce of empathy and compassion for human lives.
Yes it is, and no it woudn't. See, the problem is that Yuuya's death IS the focus of this small arc. Its the turning point that results in Kachidoki Arms.
But not even getting a smallest glimpse of what Yuuya's importance for other characters was, not seeing their reactions, or even so much as see Yuuya's disappearence's effect on the world they inhabit further removes any point for the viewer to even come close to bother with anything that comes with it. Which specifically includes Kachidoki.
No. Yuuya was
not the focus of the arc. The real crushing blow came to Kouta's ideals and beliefs that he can save people without making "necessary sacrifices".
Kouta had already gone through the anguish of seeing someone die(Hase) and came to terms with it. Consciously or sub-consciously, he's aware that the Inves they all had been fighting are all people. "Yuuya"'s place in the narrative is basically the "innocent life" that Kouta had sacrificed for his own survival(and the hope of the people). If that makes him a "device" instead of a "character" in your eyes, then that is that.
Of course, if the truth of Yuuya's death ever reached Mai and the team, it will have effects and implications, but the narrative chose for it to not be the focus of this story arc(as seen with Mitchi deliberately stopping Kouta from telling Mai about Yuuya).
Instead, it chose to focus on Kouta's inner turmoil about his battle, after being disillusioned from his ideals. And that is what's the viewer are invested in. Whether Kouta would flee from the battle(like many of us would in his shoes), whether he would yield to it and kill his compassion "for the greater good", and how can he rise from it.
