Kotlin and Swift came in to popularity around the same time. They felt extremely similar at the beginning

Kotlin put a lot of work into proving itself as something more than just a language for Android development, starting first with backend.

It seems like once KMP became viable Swift is just trying catch back up.

Opinions on this will vary, but for me Kotlin’s ties to the JVM and associated tooling is like a ball and chain. The language itself is mostly fine (though it has some weird design hangups compared to Swift), but I really do not enjoy the tooling at all. Gradle for example has me banging my head against the wall way too often.