Right now, there's only one single-codebase solution to render to android, ios, mac, linux, windows and the web - and that is Flutter.
But Flutter choosing Dart is more of an "easier to control the roadmap" strategy than the bs they actually put up on their FAQ
I'd really like a Flutter like framework (that renders to it's own widgets) but with kotlin as the framework language and it isn't impossible to make. I don't see Google making it, as it conflicts with Flutter.
Would like to see a developer oriented company like Jetpack and the open source community, make a push for a truly Flutter alternative.