Communicating form viewModel to ViewController - completion handlers?

In my view controller I have the following code:

    func handleCommentPost() {
        print("Handle post comment")
        
        if !self.customView.textView.text.isEmpty {
            if let comment = self.customView.textView.text {
                self.viewModel.createPostComment(postItem: postItem, user: self.user, comment: comment) { result in
                    switch result {
                    case .success(_):
                        self.customView.textView.text = ""
                        self.datasource.applySnapshot(with: self.viewModel.postDetailItems.value)
                        self.customView.textView.resignFirstResponder()
                    case .failure(let error):
                        print("Failed to save comment: \(error)")
                    }
                }
            }
        }
    }

and in my viewModel createPostComment is defined as:

    func createPostComment(postItem: PostItem, user: User, comment: String, completion: @escaping (Swift.Result<Comment, Error>) -> ()) {
        let userId = user.id
        let postId = postItem.post.id
        let timestamp = Int(Date().timeIntervalSince1970)
        let comment = Comment(postId: postId, userId: userId, comment: comment, createdTimestamp: timestamp)
        firstly {
            self.appViewModel.servicesProtocol.createComment(comment: comment)
        }.done { comment in
            let postDetail = PostDetailItem(comment: comment, like: nil, user: self.appViewModel.currentUser.value!)
            self.postDetailItems.value.insert(postDetail, at: 0)
            completion(.success(comment))
        }.catch { error in
            completion(.failure(error))
            print("Error creating comment: \(error)")
        }
    }

As you can see I am using completion handlers to let my controller know - from a design perspective is this ok? As you may have noticed, the properties are Combine subject properties because I was toying with the idea of subscribing to the changes rather than completion handlers, but I don't know what the right approach is here.

It feels like the completion handlers are very easy to read and understand whereas using something like Combine to notify the controller is a lot of "magic", and might be hard to follow?