I have done application development in flutter, it isnt really a great option for web yet. Its a composable object-oriented framework using widgets, rather than html/css. The benefit of Flutter is one team can do the all the dev work. You don't need separate ios/android/desktop implementations, and the backend and frontend are even often done together in one codebase.

Personally I like Flutter for apps for one reason: its cross platform and doesnt require javascript, which is an abomination, but flutter is really janky for web. Im hoping WASM will someday be a feasible replacement