We really should update that page: looking at git blame, it hasn't been touched for several years :( I'll file an issue.
Dart is used in almost every product group at Google.
- The Ads team continues to grow, with hundreds of SWEs primarily writing Dart code.
- The Google Play Console that lets app publishers market Android apps: all Dart (https://android-developers.googleblog.com/2020/06/introducin...)
- The Google Nest Hub and Hub Max devices: both the UI and a lot of back-end code are written in Dart
- Google Pay: Dart (and Flutter)
- Family Link, Google One, Stadia, Cloud Search: Flutter and Dart
Several other really big apps are being rewritten right now in Flutter. In all, there are thousands of SWEs writing millions of lines of code in Dart at Google.
And outside of Google, of course, there is the likes of BMW (https://www.press.bmwgroup.com/global/article/detail/T032861...), Sonos (https://tech-blog.sonos.com/posts/renovating-setup-with-flut...) and over 500,000 other Flutter apps that are all Dart-based.
Redmonk, the developer analyst firm, is pretty bullish on Dart: https://redmonk.com/jgovernor/2022/05/16/flutter-propels-dar...