API Gateway versus direct service to service messaging? What's the deal?

hey folks, i've been thinking about how we handle inter-service communication as systems grow. we've traditionally used an api gateway to route requests between services. but with more asynchronous processing becoming common, i'm wondering if directly using message queues (like kafka or rabbitmq) for service-to-service communication, bypassing the gateway for certain event-driven scenarios, makes more sense. what are your experiences? do you find an api gateway still necessary for all communication, or is there a tipping point where direct queueing is better? curious about trade-offs, especially around discoverability and debugging