Sure, it does fix some of the annoying things in Java, as do most languages from the last ten years. But it does also make radical moves away from it - the narrative that you could easily port any Kotlin codebase to vanilla Java becomes a complete myth once you start using delegation or async/await. From my perspective Kotlin tries to have it both ways and ends up achieving neither: it's different enough from Java that you have to treat it as a whole new language, but the lack of usable result types or structured/safe ways to do things like JSON serialization makes it looks painfully limited next to Scala. Indeed by lacking any practical way to safely report errors with information (it's missing checked exceptions but doesn't have practical result types either, because there's no "do notation"-like syntax - the "elvis operator" and friends only work with null, not with errors that carry information), in an important respect it's a regression from Java.
