Why .collect() operator in swift Combine always sends .unlimited demand regardless of the demand of upstream publisher?

I have been playing with Combine to understand how it works in more details and I create a custom Publisher, Subscription and Subscriber.

Here's how it looks..

The emoji beamer publisher along with subscription:

struct EmojiBeamerPublisher: Publisher {
    typealias Output = String
    typealias Failure = Error
    private let emojis: [String] = ["","❤️","✅","","","","","","","","❄️","","","","","✍️","","‍","","","","","","",""]
    
    func receive<S>(subscriber: S) where S : Subscriber, Self.Failure == S.Failure, Self.Output == S.Input {
        let subscription = EmojiBeamerSubscription(output: emojis, subscriber: subscriber)
        subscriber.receive(subscription: subscription)
    }
}

extension EmojiBeamerPublisher {
    private final class EmojiBeamerSubscription<S: Subscriber>: Subscription where S.Input == Output, S.Failure == Failure {
        var subscriber: S?
        let output: [String]
        init(output: [String], subscriber: S) {
            self.subscriber = subscriber
            self.output = output
        }
        
        func request(_ demand: Subscribers.Demand) {
            Swift.print("Demand: \(demand)") // Here I receive Unlimited demand
            var demand = demand
            Timer.scheduledTimer(withTimeInterval: 5, repeats: true) { [weak self] timer in
                guard let self = self else { return }
                guard demand > 0, let subscriber = self.subscriber else {
                    timer.invalidate()
                    self.subscriber?.receive(completion: .finished)
                    self.cancel()
                    return
                }
                demand -= 1
                demand += subscriber.receive(self.output.randomElement()! + " \(Date())")
            }
        }
        
        func cancel() {
            subscriber = nil
        }
    }
}

Here is my Custom subscriber:

final class EmojiBeamerSubscriber<Input, Failure: Error>: Subscriber, Cancellable {
    var subscription: Subscription?
    let receiveValue: (Input) -> Void
    
    init(receiveValue: @escaping (Input) -> Void) {
        self.receiveValue = receiveValue
    }
    
    func receive(subscription: Subscription) {
        self.subscription = subscription
        subscription.request(.max(3)) // Here I send only 3 as max demand
    }
    
    func receive(_ input: Input) -> Subscribers.Demand {
        receiveValue(input)
        return .none
    }
    
    func receive(completion: Subscribers.Completion<Failure>) {
        print("Will handle later:", completion)
    }
    
    func cancel() {
        self.subscription?.cancel()
        self.subscription = nil
    }
}

extension Publisher {
    func myCustomSink(receiveValueHandler: @escaping (Self.Output) -> Void) -> AnyCancellable {
        let myCustomSubscriber = EmojiBeamerSubscriber<Self.Output, Self.Failure>(receiveValue: receiveValueHandler)
        subscribe(myCustomSubscriber)
        return AnyCancellable(myCustomSubscriber)
    }
}

As you can see on my custom subscription I request with demand .max(3) if I don't use collect everything works fine, I get an emoji beamed every 5 second after 3 I got a .finish completion.

Works fine (and sends .max(3) demand):

let emojiBeamer = EmojiBeamerPublisher()
var cancellables = Set<AnyCancellable>()

emojiBeamer
    .myCustomSink { value in Swift.print("Random Emoji:: \(value)") }
    .store(in: &cancellables)

However if I simply add .collect() to catch all 3 results at once in an array it just requests with .unlimited demand on my subscription, resulting in a never ending subscription because my demand will never reach zero.

Never complete (and sends unlimited demand):

let emojiBeamer = EmojiBeamerPublisher()
var cancellables = Set<AnyCancellable>()

emojiBeamer
    .collect()
    .myCustomSink { value in Swift.print("Random Emoji:: \(value)") }
    .store(in: &cancellables)

Is there something wrong with my implementation? Or Did I misunderstood the purpose of .collect() operator?

Thank you in advance :)