There’s a very detailed article about GrapheneOS banking app compatibility where you can check if your bank’s app works on Graphene: github.com/…/banking-apps-compat-report/
Regarding the camera: Yes, you lost some quality with the default GrapheneOS camera app. But you can easily install the official Google camera app from the Play store (or anonymously through Aurora) to get full quality. You don’t even need Google play services installed for that to work, and you can revoke it’s network access, so it’s completely offline and private. I use the Google camera app all the time, it works flawlessly.