gitpush3442324dI used it doing angular dart and flutter.
Angular dart support is bad and lacks frequent updates, I regret using it for a side project, though our put website was fast.
As for it with flutter, it was good results in a fast app but same as react native, you need to write native code for several features that require platform features.
It's not a bad idea to learn it, but not as important to work field as Node for example
I work with flutter and so far my experience has been pretty good. I am using it for a corporate app right now and have a few well running side projects.
Dart does have *quite a steep* learning curve, especially if you come from JS because dart is strongly typed, but the experience is very rewarding. The community support on Discord is very good and so far, I've been able to find libraries for almost all my needs (charts, OneSignal, amqp).
Overall, I'll recommend working on it, but you have to be ready to invest some time.