Measuring progress
The downside of just indicating that progress is being made is that there's no end in sight for the user. This leads to a feeling of unease, like when you're waiting for food to cook in a microwave with no timer. When you know how much progress has been made and how much is left to go, you feel better. That is why it's always better to use a deterministic progress bar whenever possible.
Unlike the ActivityIndicator component, there's no platform-agnostic component in React Native for progress bars. So, we'll have to make one ourselves. We'll create a component that uses ProgressViewIOS on iOS and ProgressBarAndroid on Android.
Important Information
Due to react-native size optimization, the Meta team is working on moving such components to separate packages. In the next releases, ProgressViewIOS and ProgressBarAndroid might be moved outside of the react-native library.