I feel like I'm not on quite the same wavelength as the author. To me it felt as if a bunch of stuff about their relationship got introduced but never resolved—they still are communicating quite badly at the end. I could've sworn their relationship was still rocky. But no—apparently that's the "happy end"?
Edit: The epilogue after the side-chapters, which it only just now occurred to me to look for, gives a bit more closure, of a sort.