Kotlin dominates Android development, but Android Studio is free. Google has become more and more hostile towards indie Play Store developers, so in 2025 it is more risky and less lucrative. Kotlin's "home turf" (Android) may be losing developers faster faster than Jetbrains can gain them on other platforms.

I assume its will be a polyglot world for some time to come, and devs that decide to retool into another stack could use anything else, leaving Kotlin behind.

Android Studio is only "free" to the user.