It's less about the immediate spat and more about the slow deterioration afterward. Harry not saving Ron creates an incredible breach in what's supposed to be an unshakeable trio. The real conflict isn't just the initial anger—it’s the constant, nagging presence of that choice in every shared glance afterward. In a lot of the fics I’ve read, Hermione becomes the fulcrum, forced to choose a side or mediate, and her own loyalty fractures in ways the original story never touched. The Weasley family dynamic is another loaded gun; Ginny's reaction alone could fuel a whole novel's worth of tension, caught between blood and the boy she loves. I saw one where it all culminated in a duel at Hogwarts, not against Death Eaters, but between former brothers. That kind of internal war, where the battle lines are drawn through shared dorm rooms and inside jokes, always hits harder than another Voldemort confrontation. What stays with me are the quiet moments: Ron silently moving his things out of their shared space, or Harry spotting him across the Great Hall laughing with Seamus and Dean, realizing he's been replaced in the ecosystem of Ron's life. That's the stuff that lingers.
You can also branch into how it changes Harry's mission. Without Ron's grounded, humanizing influence, Harry can spiral into a darker, more isolated version of himself, obsessed with the Horcrux hunt to the point of self-destruction. The conflict becomes internal as much as external—Harry wrestling with his own guilt and hero complex, wondering if letting a friend fall was the price of being 'The Chosen One.' It reframes his entire journey as a potentially tragic one, where winning might mean losing everything that made the fight worth it in the first place.