If you actually have someone you consider a legitimate friend, this ending hit hard. I love my boy like a brother but I couldn't throw away hundreds of lives (many of which are kids that haven't even had a chance to truly begin living yet) away for one. It's actually tragic. Chloe was doomed to die a premature death and to a degree, Max was doomed because while she lived, she had to resound herself to a life of grief & solitude since she'd live with knowing she could have saved her best friend from death but didn't, or a life of guilt and anxiety because she directly contributed to the death of countless of innocents.
The ending fukked me up more than I thought it would. Lingered on my mind for a couple of days after completion. I really felt for those girls, man.
Edit: I also think some were too hard on Chloe. Did she get on my nerves at times? Absolute-fukkin'-lutely, but the kid had lost her father in her formative years (and later lost her best friend/romantic interest in Rachel due to a rape & murder.) Max moves to the other side of the country and completely ghosts her for years right after her dads death, leaving her essentially alone. Everyone handles grief differently. She's dealing with all that loss while becoming of age at the same time. Teenage politics, peer pressure, hormones. Chloe was understandably flawed which is what made her human to me.