There are three basic categories of fic writer:
type one: fan fiction is a love letter to canon, only small changes unless it’s an au!!
type two: the source material can bite me, I don’t give a fuck
type three: horny
sorry, I forgot one
type four: canon COULD be so good if it wasn’t so straight/white/horny, so I fixed it while holding unblinking eye contact with the creator and mouthing ‘die’
Two, Three, Four. Guilty.
Two, three (sometimes) and four. Yup.
two and four
Two, three and four in various combinations.