Why not use sealed interface over sealed class for children definitions?

[YektaDev]

Hi. As you know from the title, I wonder why the examples available in docs use classes in cases like this:

interface Root {

    val childStack: Value<ChildStack<*, Child>>

    sealed class Child {
        class List(val component: ItemList) : Child()
        class Details(val component: ItemDetails) : Child()
    }
}
// ...

... when we can instead use:

interface Root {

    val childStack: Value<ChildStack<*, Child>>

    sealed interface Child {
        class List(val component: ItemList) : Child
        class Details(val component: ItemDetails) : Child
    }
}
// ...

Is it solely a matter of personal preference or are there other reasons for it?

[arkivanov]

I don't remember exactly and can't verify now, but this might be for better interop with Swift. Otherwise, feel free to use sealed interfaces if you like.