> But in the end, nothing can BEAT^) natives, Kotlin for Android and Swift for iOS
^) 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.