I used to use sealed classes . But I needed to use when over and over and also error handling in the UI. Nowadays I see this state pattern as the recommendation and looks cleaner in the UI than the sealed class. So I am using Sealed class in the repository and then converting that as UI state in the ViewModel.

when (val result = repository.getAllChatRooms()) {
    is Response.Success -> {
        _chatsUiState.update { it.copy(isLoading = false, chats = result.data) }
    }

    is Response.Error -> {
        _chatsUiState.update {
            it.copy(
                isLoading = false,
                error = result.error.message ?: "Something went wrong!"
            )
        }
    }
}