Let’s see if it’s smart 10 years from now. Cross platform toolkits that draw their own widgets tend to have a hard time keeping up longer term and Google isn’t really known for the constance regarding project management.
If they “only” pull another AngularJS -> Angular transition. and it’s already a bad thing. If they abandon it, ouch!
Have you looked at Uno?
C# & XAML UWP layer with Xamarin for mobile. The company behind it has been using for a few years to produce apps and recently open sourced it. I'm intrigued and weighing it against Flutter for my next bit of mobile experimentations.
But looking into Flutter, I think it's undeniable how smart this project truly was. Even if it isn't backed by a popular programming language, since Dart obviously does not fall on that category.