I haven’t really had a great experience with Flutter in the past, in my opinion I think React Native provides a better user experience. Developer experience is okay.
The best experience for users would be a library that handles business logic, as well as describes how the UI should be laid out, then building native clients that use that library.
The best experience for users would be a library that handles business logic, as well as describes how the UI should be laid out, then building native clients that use that library.