I agree, it feels a bit odd as of now, but I think a lot can be resolved if a lot of people just try it and create wrappers/libraries for it. If Kotlin/JS were a language on its own it would surely fail, but due to Kotlin getting popular in the Android/Java space I think it has a chance. I think it will first start in NodeJS based servers though, as a way to provide a single codebase and the same business logic for both the app as the server. I think if Google for instance would decide to provide Firebase Functions with Kotlin as first language, just like Android, libraries and wrappers would come a lot faster.
I don’t think Gradle would be a problem as I think most people trying Kotlin/JS are coming from the JVM world anyways and especially with multiplatform Kotlin libraries, you kinda have to use Gradle. The npm/Gradle integration needs some work though…
Obviously as standalone framework would be great. One bright light is Multiplatform libraries. If those improve it doesn’t matter what platform you target as long as you use only those libraries. Imagine creating a single UI that works in web pages, android apps, iOS etc.