In the age of LLMs, I get why you would dump portablity in favour of close-to-the-metal Swift and Javascript codebases. However I don't really understand the need for Kotlin- surely thats just an unnecessary complication and performance hit?
Kotlin compiles to the same JVM bytecode that Java itself does. There is no performance hit. And from a developer's perspective, no it is not a "complication", Kotlin is a much more pleasant and efficient language to program in than Java (in my opinion, and that of many others).
That's for the Android version, I would assume