I have finished The Secret History and you're invited to gather for my hot take: you have to be able to give Bunny enough grace to believe he could have grown up to live a mediocre life for the tragedy to truly have an impact.
No, I don't think he would've got his masters in art, fallen in with a group of socialists, got a little bi-curious, and overhauled his entire ideology.
I also don't think he would've dropped out of school, bummed around his father's house until he inherited it, and posted prolifically on right-wing forums.
He probably would've married Marion right out of school, dodged the workforce until his first child was born, then struggled to hold down a job and likely got involved in a couple of pyramid schemes on the way. He'd be the kind of dad who'd tell his friends he was "babysitting" at the weekend, and when it was his turn to cook they'd be having microwaved pizza. In all honesty, they'd likely divorce within the decade.
But he'd love his wife and he'd tell that to anyone who would listen. He'd want to provide for his children in a way his father never provided for him, even if he'd struggle to do so. Despite holding the belief that childcare wasn't his "responsibility" he would put his kids before everything. Even after the hypothetical divorce.
And while his family had clearly ingrained some dangerous prejudices throughout his life - several of which stuck - he was also an artist, enjoyed travel, had a disability and a chronic health condition, and (miraculously, somehow) had no trouble making friends with women and queer people. There were so many spaces he was part of that he could've learned, given time and a different setting, if not to be more open and caring then at least to not be such a loud mouth.
It can't be "Bunny was the best of them and deserved to die the least" or "Bunny would've grown up to be a wife-beating M*GA supporter, thank god they killed him." It's "Bunny had his whole life ahead of him. At 24 he hadn't had the chance to experience what adulthood is really like due to choices his parents made for him when he was younger. He had the potential, still, to be a million different people, but that was taken away from him." That is the tragedy.