@abhinay i think it’s really important and in line with XCode / Interface Builder from Apple. If you have a lot of .fxml chunks, you still have to assemble them in a working app. In that case, the app is responsible for the navigation or the transitions between the different views. XCode has drag-and-drop features that link code to UI components. Also, there are Segues which represent the predefined transitions.
I haven’t used XCode with MacOS software, so for the iOS stuff I did, it’s simpler than a desktop app. There’s only one UIView at a time.