Failed to take over the Web as Chrome team was driving it, then ChromiumVM got dropped, several key designers like Gilad Bracha and Lars Bak left the project, it was ultimely rescued by AdWords team, which had just migrated away from GWT into Dart, got rebooted into a strong typed language with type inference, and picked up by the Flutter team.

Nowadays it is basically a language to write Flutter applications, hardly worthwhile to bother using it for anything else.

Flutter is taking place on Google politics, while Google lets Flutter, JetPack Composers and PWAs play the game of cross platform GUI frameworks, with the difference that Kotlin and JavaScript/TypeScript have a much broader eco-system than Dart.

In my opinion it's not an especially compelling language (yet maybe it evolves into one) and is useless outside of Flutter. It feels shoehorned into the project because Google wanted to find a use for it. It simultaneously alienates mobile developers and cross platform developers by picking a language neither have experience in and neither can use outside of this one framework. There are people taking about Flutter being to Dart what Rails was to Ruby so maybe time will tell. Flutter itself seems decent though, despite a few oddities.

The compile time guarantees could have been much better, especially around null pointers. Now they're hacking in non-nullability the same broken way they did it in Java. Same goes for a lot of things like switch / case statements requiring breaks but not supporting checks for covering all cases compile time.

In general it just feels like old Java spiced up with some Javascript niceties like Futures and a nice constructor syntax.

But you should've noticed that coming from Kotlin?

Why wouldn't they use Kotlin as most mobile developers are already used to it?