The question is not whether you want your application to be cross platform. After ~10 years of app development I can say that in almost every case I do want to

The question is not whether you want your application to be cross platform. After ~10 years of app development I can say that in almost every case I do want to share codebases. The real question is "where do you draw the line for cross platform code?". In other words, do you want everything to be potentially shared or do you only want the "business logic" to be shared? Unless theres a real constraint on time, I've found the best option to be starting with shared core + native views and migrating the view logic into the shared core over time as you discover the UI patterns. You can have native feel by using a framework that binds to the native directly. In my opinion Xamarin is the best option currently, but Kotlin Multiplatform is a possibility once they mature.