I think Flutter is better _because_ it uses Dart. I used to hate that decision ("Not another language to learn.."), but Flutter and Dart are like Mac and macOS (I'm aware people complaining about macOS quality going down the hill.. but that's another story). They're both from the same company, seemingly built for each other, and the language (Dart) improvements are _relevant_ for the platform (Flutter). Flutter still…
It's like going from Kotlin to Java, or Swift to ObjC, or Typescript to Js. Tooling stinks, language features are missing, ergonomics are bad.