Kotlin is weird in that it is fully compatible with Java, so you can reuse all the existing Java libraries, which was the primary argument there.
Embrace-extend-extinguish is a tried and true strategy to overcome entrenched languages, I suppose.
But, like, it literally doesn't? The fact that it's a different language nowadays (though still the same runtime?) means that there's no One True Language for Thing X. Times change. Today it's FooLang, but in a couple of years, when the stars align just right, it may be LangBar.