Google released their new React Native alternative called Flutter and with Flutter comes their new programming language, Dart.
Google would not like to be left behind but it would also not like to conform to other companies and rely on Facebook for their stability. Google solved this conundrum by creating their own framework like React Native called Flutter. Flutter uses a Google-like design called Material and also uses another programming language called Dart.
As per usual, Google has made switched all of its apps to Flutter. This is why you know when an app is made by Google. Material Design is Google's look and everyone thinks of Google when they see it.
Although most apps use React Native, many great apps are coming from Flutter too and they all look great. Many Flutter apps have turned out great and they look amazing because of the CSS/SASS integration.