One angle that's genuinely compelling in those stories is how they untangle the messy mix of initial judgment and social pressure. Instead of the canon 'okay, I was wrong,' fanfic writers build entire internal monologues around Darcy's anxiety over his family's legacy or Elizabeth's quiet panic that she misjudged a man who might be kinder than her wit allowed her to see.
I'm less convinced by fics that push them into dramatic external plots to 'prove' their growth—kidnappings or inheritances lost. The real territory seems to be in those small, awkward moments after the confession. A writer I follow does this brilliantly, having Darcy stutter through explaining his estate ledgers to her, not to impress but to include her, while Elizabeth fumbles with admitting she enjoys his dry letters. The growth feels earned because it's clumsy, not cinematic.
You can trace it by the shift in their internal voices across a story: early chapters use sharper, more defensive language for both, which gradually softens into observation and curiosity about the other's perspective. That textual mirroring of emotional thaw is what hooks me.