The native executable is smaller indeed.Yet, you can still look in direction of jpackage and GraalVM native image (they are both still larger than K-N binary). I am not so sure it is worth it in a general case, but there could be cases where it is important. As I already said, it makes sense to use native when you have some kind of hardware specialization.
The average performance of native applications (and I do not mean only Kotlin Native) is not as good as JVM because of JVM JIT (and the amount of work put into it is hard to replicate) together with memory management. You can’t write effective modern application without some kind of memory management and,again, it is hard to replicate the amount of work put into JVM GCs.
Of course there are always systems programming fields, where you need manual memory management and manual hardware specialization for the code. There you should use special tools like Rust and maybe Kotlin Native (in future).