I haven't looked too deeply into how BeeWare works, but why is it so uncommon to see similar solutions in other languages like Kotlin, Go, Rust etc? Basically the React Native approach but without JS. I would love to write multiplatform native UIs in any of these languages.
I have nothing against Javascript but there are still a lot of weird limitations in RN despite being several years old. Writing smooth animations that support user interaction is difficult because it is still single threaded and you are limited to a declarative animation api where the underlying native runtime does the interpolation.
React-reanimated v2 tries to solve this by spawning JS worklets that can run animation code in another thread but that comes with its own caveats. This would be so much easier to do in a language with built in threading, not to mention all these languages are very ergonomic and loved by developers so I'm curious why something similar hasn't been tried for them yet.
For the languages it boils down to availability of relevant ecosystem and developers in my experience.
Why react-native, well, because it means you have access to one of the largest ecosystems and an awesome tooling catalogue. The same applies for JS as the language of choice for App (UIs). Kotlin was also a great candidate since it could leverage the already mature Java ecosystem for android.
Flutters success is an outlier here that I would guess is due to Google backing. The resources and docs are good and you could rely on financial and developer backing. The decision to go with Dart was most likely to make themselves not dependent on another party for a core utility and to have a steering position on the overall projects course.
If, for example, Microsoft would back a good C# cross-platform framework I would bet on it at least seeing moderate adoption.
Edit: As another commenter pointed out, GO has a cross-platform GUI Framework option - Fyne [https://github.com/fyne-io/fyne]
I have nothing against Javascript but there are still a lot of weird limitations in RN despite being several years old. Writing smooth animations that support user interaction is difficult because it is still single threaded and you are limited to a declarative animation api where the underlying native runtime does the interpolation.
React-reanimated v2 tries to solve this by spawning JS worklets that can run animation code in another thread but that comes with its own caveats. This would be so much easier to do in a language with built in threading, not to mention all these languages are very ergonomic and loved by developers so I'm curious why something similar hasn't been tried for them yet.