Besides Dart v1.0, Dartium, Angular Dart when they were still relevant to Chrome and Angular teams, and following up on Flutter?
I usually only criticize stuff that I actually have some level of experience with.
AdWords team rescued Flutter, after Chrome and Angular teams stop caring, which even caused Dart designers like Gilad to leave in disagreement.
I believe that they found out some internal management support that is willing to give them a time frame, of lets say 5 years to prove themselves worthy of such support.
Android has more political power ChromeOS has adopted Android and not the other way around, the two commercial OSes from Google.
While their experimental OS, Fuchsia is now adding support to run ART, while at the same time via Scenic, decoupling themselves from the UI framework.
You want to believe in Dart/Flutter, go for it.
Me, I am betting it will be joining the list of abandoned Google projects in a couple of years.