Basically because a UI framework's usability is directly related to how idiomatic it feels. So if you write a UI framework in C for C, it will feel nicer than a

Basically because a UI framework's usability is directly related to how idiomatic it feels. So if you write a UI framework in C for C, it will feel nicer than a UI framework in Python for C, or in C for Python. This directly translates into how productive developers can be using the framework, which is one of our top priorities. When we started, about 3 years ago now, we looked at many languages (dozens of them) and, objectively, Dart was the best fit for what we wanted to build. At the time, "we" was a few people from the Chrome team, and me (HTML spec editor at the time). We were all Web people, whose only impression of Dart was somewhat like negative comments in the thread here. When we studied each language, though, we found that impression was really not relevant to Dart as a language for mobile, and in fact it fared better in our comparisons than the other languages we looked at. I think it would make a lot of sense for people to create other projects very similar to Flutter where Skia is combined not with the Dart VM but with other languages, and for the Flutter framework to be ported -- in a language-idiomatic manner -- to those other languages. I can totally imagine, for instance, a TypeScript-based UI framework like Flutter, or a Kotlin-based UI framework like Flutter, or a Swift-based UI framework like Flutter. After all, in many ways, Flutter is just an evolution of previous UI frameworks like React, DOM/CSS, UIKit, and Android views. Let a thousand flowers bloom. One day I hope I can write my mobile apps in FreePascal using a reactive framework with a design evolved from Flutter. :-)