Another take on that is that he wasn’t going to war for his school at all. That’s ignoring the previous comments about it not being about the school at all (which is partly true), but recognizing the validity of that perspective.

My point is that even if the war had been about the school itself, that wasn’t what Harry was fighting for. He was fighting for his home…

Books or movies, Hogwarts was the one place that Harry felt was home. Not the Durselys’, not even the Weasleys’. Hogwarts was Harry’s first real home. So, even if he hadn’t been the “chosen one”, even if voldemort was attacking the school directly as a goal without any of the rest of the part about him and Harry, I think he still would have fought as hard as he could to defend it.

You could make Harry a supporting character with his parents just having died of natural causes, and him being taken in by the Dursleys to eventually go to school at Hogwarts with nothing else involved, and that kid would still have fought for the one place he felt at home. Hogwarts was like that for other students, but Harry had that abusive household and extremely limited freedom to make other social connections. That’s an ideal setup for someone to attach to something as wonderful as Hogwarts was in comparison.

I really think that Harry would have fought just as hard or harder for no other reason than that.