Dart itself has also made a huge amount of progress in the last 2-3 years and are days away from probably their most significant upgrade ever.
Dart is at this stage actually a damned good language. Miles in front of TypeScript for example.
Simple example here looking at Mixins (a fairly basic pattern to describe any kind of a “is-a” rather than a “has-a” relationship in OOP).
Here’s TypeScript
https://media.infosec.exchange/infosecmediaeu/media_attachme...
Here’s Dart
https://media.infosec.exchange/infosecmediaeu/media_attachme...
When Dart finally gets around to releasing their updated web and JS interop support later this year it is almost certainly about to become my new default there too.