In romance reading spaces we talk a lot about the journey. If I present to you main characters that hate each other, it's not a shock to discover they learn to like each other and fall in love. If the main characters decide to fake date, it will likely not surprise you that much to learn that they develop real feelings.
I am a huge spoiler-phobe, but some things are not really spoilers.
I was listening to the Proxy podcast, and they talked about the use of proxies in restorative justice. (Quick note: the episode itself contains discussions of sexual assault.) Restorative justice is a process through which those who have harmed, and those who have been harmed work through how they can come to a place of healing.
I think our society sometimes tries to leapfrog to the end. Like, yes, you were harmed, but I'm sure they are sorry, you should forgive them so you can move on. And yes, moving on is a good idea. Eventually. And sometimes the person who harmed you is not ready, or dies, or is otherwise unavailable to provide anything like closure.
But skipping to forgiveness, or declaring something closed doesn't do it. There's still a process. I have to tell you, I often hate having to stew in my feelings. Or let time do some of the work. (Time? What? Ridiculous.) But the journey.
Because a story about people meeting and then skipping ahead to them being happily in love is not a satisfying read. I could just read wedding announcements if I wanted that. (Not that there's anything wrong with reading wedding announcements.)
And I think that's also why I like the third act breakup. It isn't the only way to structure a romance. But in relationships, people harm each other, often unintentionally. One way to signal that these people can survive these bumps, is by showing them hitting a bump, and then showing them figuring out how to repair it.
Getting to see the specific ways characters address this is interesting to me. And I wouldn't want to skip past that.