^) my edit
Note that Flutter is conceptually a completely different (and more powerful) animal, in the sense that it removes the distinction between the system code ("native") and the user code ("app").
The app basically includes its own GUI library, and only calls the system to do I/O. The OS provides the events and a drawing surface, that's all. Importantly, to the app there is no hidden state to manage (and debug).
So one might argue the reverse (also up to a point): nothing beats having access to your own state, so nothing can beat Flutter.
And why is there yet another need for this? Because phonegap, ionic, xamarin, react-native were not good enough.
Unfortunately, have had to code for all of these abstraction tools. There is no silver bullet, just trading one pain for another. Why learn the native language? When it is funner to debug thru layers of abstraction.
Even airbnb is moving back to native, from react native. The pain was not worth it.
