I agree, that term feels better suited to what we experience.
My husband is a better person, father and husband because of the emotional growth that happened post-DD. I like and respect the man he is now so much more than the emotionally stunted, resentful man he’d become in his late 30s, early forties.
He is so much kinder, gentler, more understanding of other people’s vulnerabilities and issues now having had to face his own.
But like you, I can never say I am happy for his affair, because I refuse to believe that the only means by which those results could have been achieved was for him to hit bottom. To become a person he loathed, acting in ways that he, himself, thought were despicable but couldn’t seem to stop. That having a crisis of identity of epic proportions that very nearly burnt everything in his life down was the only way he could force himself to look within and face his demons.
Of course I could be wrong - maybe some people have built their wall of denial so high that it is only through catastrophe that it can come down. But if so, I sure as hell wish they’d come with a warning label attached.
Regardless, the term collateral beauty seems better suited to describe that bizarre realization that out of all this horror, pain and despair could come some good things too. I think it takes a long time to come to terms with that (it did for me). That by accepting and even being grateful for the good things that arose from the ashes didn’t mean I was condoning what precipitated them (the affair).
We already experienced the collateral damage, we deserve to allow ourselves to find, see and enjoy the collateral beauty as well.