I get where you’re coming from, and I do feel like Chani really suffered from the adaptation, but I felt like it was more due to screentime and not having internal thoughts than changes made. I felt her being skeptical at the beginning was both a great change to her character (it feels like she falls in love with the Muad’dib Paul becomes, not the Atreides he was) and a really good way to carry themes of anti-messianism into the movie where the book relied on philosophical asides. It also provides a natural foil to Stilgar’s zeal and Jessica’s manipulation, presenting Chani as more aligned with Paul himself.