There are two mobile platforms: Apple iOS and Google Android. Each mobile platform has changed its preferred language: Objective-C -> Swift and Java -> Kotlin. There are two popular language-specific cross-platform mobile ecosystems: Google Dart and Microsoft C#. The article excludes the hybrid mobile/web cross-platform approaches that use JavaScript/JSX such as PWAs and React-Native. The preferred mobile platform IDEs, Xcode and Android Studio, seem to be as central to each mobile platform as the programming language.
It seems to me that the important questions each developer must ask are:
1. target mobile platform(s)?
2. greenfield vs. brownfield app?
3. current skillset?
The ideal language falls out of these questions, IMHO, but there are a multitude of edge cases that may apply.
I know, I know but never could make the transition.