[radley]

I think everyone jumped from Java to Kotlin due to Oracle suing Google over Java in Android. It also provided a huge opportunity to be more deliberate since Android was maturing.

[nazgulsenpai]

Oracle sued Google over the Android's implementation of Java's API. Kotlin still uses those APIs as it is compiled to Java bytecode on Android.

[pjmlp]

That is an urban myth.

If that was the case, they would have adopted Dart instead of keeping an high dependency on the Java ecosystem for Android.

Android Studio, Gradle, Kotlin compiler, the libraries that Android depends on from Maven Central, all Java.