You didn't even knew about its use in Nest Hub Smart Displays.
I know how Flutter is implemented, thank you very much.
Most likely is a very thin layer over existing Google Earth C++, unless you have some proof the C++ code was fully rewritten into Dart, beyond a simple tweet.
And I don’t know what you think Flutter is built with but it’s C++ / WebAssembly and WebGL.
https://x.com/FlutterDev/status/1708908434068779376