All the best for them, as long as the community takes the attitude to appreciate JVM and Java for giving birth to Kotlin, instead of bashing Java as if Kotlin could stand on its own.
I respect your knowledge and breadth of experience, but your biases are apparent.
Yes I don't hide what I think out of political correctness, it is up to the receivers to deal with it.
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!
And this has a price. Bad language features stay, they make it difficult to introduce new stuff. Also, Java is very conservative in picking up new things. Saying "once Java has caught up" ignores that Kotlin, at that point in time, will be even further ahead of Java most likely.
And both of them will never reach feature parity with Scala. ;)
It just hasn't shown to be a race to feature parity in practice. Enough of the Kotlin and Scala user bases just really do want a better Java, often in just one or two ways.
Personally, and more controversially, I don't think Java getting pattern matching in switches or sealed classes is going to move the needle a ton. (Sorry, Brian!) It's going to be Loom and Records that really change things.
This assumes that there is much "ahead" to get and that people want more features (well, some do, but the vast majority don't seem to). If the "catching up" terminology applies at all, it certainly doesn't mean feature parity with every other language. That's like a compulsive hoarder seeing a neighbour buying a lawn-chair and saying, "nice to see you finally catching up!" Once you've "caught up" with the expectations of the majority of programmers, there's not much more catching up to do. Neither Scala nor Kotlin have broken past 5% share of the Java platform, even when Java was behind mainstream expectations.
So sure, there will always be some small percentage who like more features than the mainstream fashion, but it's been clearly shown that you can't appeal to that minority and to the mainstream majority at once. Java (the language) tries to appeal to the latter, not the former.
You have a point there - maybe the "catching up" is not relevant to the majority of the developers. I always find that surprising but I think you are right.
Also, everyone in this thread is talking about Loom and Valhalla. Are those actually going to land at some point? I was starting to assume they were vaporware.