Kotlin and Java: A Natural Successor to Java

My understanding is that like sort of Kotlin and you mentioned Groovy as well. The JVM itself enforces essentially the ABI between all of these components. And in order to use something like C++ you actually need to look at the header files and understand them. So do you see that there's obviously from the point of view of Kotlin being a natural successor to Java, I understand that but I think it had fewer problems or am I misunderstanding?