message queues when is it overkill

we've been using Kafka pretty heavily for inter-service communication, and it's been fantastic for decoupling and handling spikes. But I'm starting to wonder if we're using it for *everything*. For simple command-and-control between two services that are always up and available, is the added complexity of a message queue really worth it compared to a direct HTTP call, what are your thoughts on the tipping point where a queue becomes more of a burden than a benefit