Totally valid point that swift is only useful for developing for Apple products, but this same criticism also applies more or less to Kotlin on Android. If you are dealing with iOS it is a joy compared to objective C. I would also add that it is a really nice language in general that is modern, expressive and general ergonomic.
Further to that point, Kotlin mainly targets the JVM (which can run pretty much everywhere), but also can be compiled to JavaScript, LLVM, and a bunch of other targets.
Honestly the only times I've evaluated Kotlin for personal projects was bc of that flexibility.
With various levels of implementation quality, Kotlin/Native had to be rebooted, on JS it hardly offers anything better than TypeScript, on the JVM it is mostly used by Android shops anyway.
It was adopted on Android quite fast after Jetbrains made the integration in Android Studio almost flawless, partly because back then the Android runtime was stuck on the Java 6 syntax plus some syntax sugar that the IDE provided to mimic lambda functions.
It helped a lot that I think Jetbrains took advantage of all they could to make development in Kotlin very smooth, I remember back then people joked how Kotlin worked so flawlessly on Android Studio almost like it was the main language while on Xcode Swift was slow, the highlight would stop working constantly, refactoring was not supported, often indexing the project would hang forever etc.
I think everyone jumped from Java to Kotlin due to Oracle suing Google over Java in Android. It also provided a huge opportunity to be more deliberate since Android was maturing.
> this same criticism also applies more or less to Kotlin on Android.
i think kotlin has more use outside compared to swift.
But a language has to start somewhere, so i wouldn't hold it against swift. It's a fairly well done language regardless, and nothing apple specific about it tbh (which are all just libraries).
An example is smart contracts on the Corda blockchain, which is programmed in Kotlin. It may be me, but I have seen more Kotlin outside of Android than on it.
