If you're looking for a reason as to why Camila Cabello left Fifth Harmony, let me help you out a little bit. It's because she wanted to write her own music. Well, that's at least one of the reasons.
She told the New York Times "I was just curious and I wanted to learn and I saw all these people around me making music, writing songs and being so free," She also said that she wanted to write for Fifth Harmony but wasn't allowed to.
“It became clear that it was not possible to do solo stuff and be in the group at the same time," Camila said. "If anyone wants to explore their individuality, it's not right for people to tell you no."