when do you start using a message queue, like, when does it become a good idea

Hey everyone, I've been thinking a lot about asynchronous processing lately. We're running into some bottlenecks with synchronous calls that directly impact user experience. I've seen a lot of systems use message queues (like RabbitMQ, Kafka, SQS) for decoupling services and handling background tasks, but I'm not always clear on the exact trigger point for introducing one. What are your experiences? When did you decide a message queue was the right move for your architecture?