Scrolling.

Simple as that. Using a flutter app has non system scrolling acceleration, scroll speed etc.

It doesn't feel like a native app, because it isn't a native app.

With react native, there are many parts of it that use the underlying system's UI, and so it feels like it could almost be a native app.

Also hitching their horse to dart was a poor move to get devs to switch over from swift/kotlin and JS.