when do you use message queues for inter-service communication?

hey everyone, i've been thinking a lot about how services talk to each other lately. we've been relying on direct http calls mostly, but i'm starting to wonder about message queues. what are your go-to scenarios for introducing a message queue like RabbitMQ or Kafka? is it just for decoupling, or do you find them essential for other reasons, like handling traffic spikes or ensuring eventual consistency? curious to hear your experiences and the trade-offs you've encountered