Not to the same extent. Scala.JS and Kotlin.JS are somewhat comparable, other targets not so much. There was no serious attempt at making Scala target mobile devices, even during the window of opportunity with Scala on Android.
> even during the window of opportunity with Scala on Android.
I don't understand this. You can run any pure Java jar on Android, pretty sure you can do that with Scala too? It's not exactly a "different platform" in terms of programming language. Sure it needs tooling and specific libraries, but that's higher level than the programming language.
Jetbrains is doing interop with Swift (Kotlin -> ObjC -> Swift and more recently Kotlin -> C -> Swift), which Scala never did. But I don't really see how this is relevant in this conversation.
You can run Scala on Android and it's been done but it never worked well nor was given priority. Which is understandable as the commercial entities behind Scala already struggle to build the ecosystem and tooling in spaces where the language shines.
For instance the Android runtime has chronically lagged behind mainline JVM bytecode versions, iirc once Scala started to emit Java 8 bytecode, Android was stuck on Java 6.
Kotlin had other obvious advantages on Android like its thin standard library or the inlining of higher-order functions.
