The presence of native widgets is both in Flutter and React Native (e.g. in Flutter you can import material UI widgets or Cupertino/iOS style widgets)

However,

Flutter compiles to native code which allows for high performance. The code is translated to UI on a pixel-to-pixel basis.

React Native uses a JavaScript runtime called JavaScriptCore which may be more limiting compared to Flutter.

So which one is truly native? I lean towards Flutter in this case.