Kotlin is definitely available at Google, but when talking about sym types et al it's not nearly as nice to use as Rust / OCaml.
I definitely find it (and jetpack compose) make developing android apps a much better experience than it used to be.
What I like a lot about Kotlin are its well written documentation and the trailing lambdas feature. That is definitely directly OCaml inspired (though I also recently saw it in a newer language, the "use" feature in Gleam). But in Kotlin it looks nicer imo. Allows declarative code to look pretty much like json which makes it more beginner friendly than the use syntax.
But Kotlin doesn't really significantly stand out among Java, C#, Swift, Go, etc. And so it is kind of doomed to be a somewhat domain specific language imo.
If that wasn't the case, Google would support Java latest with all features, alongside Kotlin, and let the best win.
See how much market update Kotlin has outside Android, when it isn't being pushed and needs to compete against Java vLatest on equal terms.
Kotlin has a very similar syntax to Groovy, which already had that feature (it looks identical in Groovy and Kotlin)... and I believe Groovy itself took that from Ruby, I believe (Groovy tried to add most convenient features from Python and Ruby). Perhaps that is what came from OCaml?? No idea, but I'd say the chance Kotlin copied Groovy is much higher as JB was using Java and Groovy before Kotlin existed.
In many use cases even if the performance is within the project delivery deadlines there will worthless discussions about performance benchmarks completly irrelevant to the task at hand.
And ironically many of the same folks are using Electron based apps for their workflows.
