I agree with pjmlp (and I don't even work for Oracle!). I think that once Java has caught up with pattern matching syntax, data classes, fully integrated Loom and Valhalla etc there really isn't a need for Kotlin on the server-side anymore.
For Native or frontend stuff it's definitely always going to have to play catch-up and try to shoehorn wildly different semantics into the same language somehow.
So I guess it'll end up as a niche language on Android, ultimately. Not necessarily a bad place to be, though!