Are you talking about building an Android app?
Each language does something well. If I was building AI python would be my first choice.
Welp, guess all my Spring Boot web apps in Kotlin have actually been Android apps in disguise all this time..
I have used Kotlin for web services and, while I prefer Scala or plain Java for that, some of my colleagues prefer the Kotlin syntax and features.
> what you get out of the box doesn't compare.
Would you like to elaborate here? I have used Rails and Django and they get you a lot out of the box.
That still doesn't change the fact that, when you master hammers, you still have no idea of how to correctly use a screw.
Every language comes with some blind spots. Learning different languages is often enlightening because it forces one to see the solution space with a different kind of glasses.