I am new to Azure Service Bus, I'm looking into whether it can replace our RabbitMQ infrastructure.

Anyway, I was wondering if there is a point in using Queues at all? If Topics and Subscriptions offer the same capabilities + provide the flexibility for consuming independently from multiple sources.

For example, if right now I have a setup with just a single consumer group (might be multiple consumers, but all sharing the same messages queue), I could work with a Topic that has a single subscription.

What is the point in Queues? Does it provide some sort of optimization over Topics and Subscriptions?