Earlier quoted context omitted.
They all have the same issues, but RN has the largest community.
Flutter has a larger number of "star" on Github. It also has more issues and more pull requests. React Native has 3x more followers on Reddit. So I guess it depends on your definition of community.
RN is ready now and today for all platforms, including Window via react-native-windows.
Microsoft is choosing React, I wouldn't go w/ Flutter.
Why would you choose a Google only language and framework... unless you like rewriting code when it dies.
Also, w/ React you can use TypeScript or JS, you don't have to learn a new language.
From my perspective, it looks like Google pays a lot of money for these tech articles and stars, it's not a really good way to look at things. There's always a Flutter campaign going on.