The React Native reason is called C++/WinRT, the teams that internally rioted against C++/CX and came up with C++/WinRT (now in maintenance, go figure), never cared one single second about the Visual Studio experience (using C++/CX was similar to the Delphi/VB like experience from C++ Builder), that everyone else was losing.

Thus React Native is the only alternative left those teams had to have some kind of nice GUI design experience alongside C++/WinRT, when using WinAppSDK, think Qt with QML/C++.

Agree on the Flutter comment.