React Native init:

Advantages

  • You can add native modules written in Java or Objective-C (probably the only but the strongest one)

Disadvantages

  • Needs Android Studio and Xcode to run the projects
  • You can't develop for iOS without having a Mac
  • Device has to be connected via USB to use it for testing
  • Fonts need to be imported manually in Xcode
  • If you want to share the app you need to send the whole .apk / .ipa file
  • Does not provide JavaScript APIs out of the box, e.g., Push-Notifications, Asset Manager, they need to be manually installed and linked with npm for example
  • Setting up a working project properly (including device configuration) is rather complicated and can take time

Expo

Advantages

  • Setting up a project is easy and can be done in minutes
  • You (and other people) can open the project while you're working on it
  • Sharing the app is easy (via a QR code or link), you don't have to send the whole .apk or .ipa file
  • No build necessary to run the app
  • Integrates some basic libraries in a standard project (Push Notifications, Asset Manager, etc.)
  • You can eject it to ExpoKit and integrate native code continuing using some of the Expo features, but not all of them
  • Expo can build .apk and .ipa files (distribution to stores possible with Expo)

Disadvantages

  • You can't add native modules (probably a game changer for some)
  • You can't use libraries that use native code in Objective-C/Java
  • The standard Hello World app is about 25MB big (because of the integrated libraries)
  • If you want to use: FaceDetector, ARKit, or Payments you need to eject it to ExpoKit
  • Ejecting it to ExpoKit has a trade-off of features of Expo, e.g. you cannot share via a QR code
  • When ejecting to ExpoKit you are limited to the react-native version that is supported by ExpoKit then
  • Debugging in ExpoKit (with native modules) is a lot more complicated, since it mixes two languages and different libraries (no official Expo support any more)

Sources: