This article talks about the benefit of a message bus being pub/sub. This definitely helps to decouple the internals of apps, which in turn makes things easier to maintain.
There are many other benefits to using a message bus, and it's a better fit in general to distributed systems. The hard part is understanding how to structure apps to make them compatible with messaging.
Imagine sending out a command to the bus and not knowing when it'll get processed. Perhaps under a second, perhaps next week. You can't expect a reply at that point because the service that sent it may no longer be running.
There are many other benefits to using a message bus, and it's a better fit in general to distributed systems. The hard part is understanding how to structure apps to make them compatible with messaging.
Imagine sending out a command to the bus and not knowing when it'll get processed. Perhaps under a second, perhaps next week. You can't expect a reply at that point because the service that sent it may no longer be running.
If you're on Node, try https://node-ts.github.io/bus/
It's a service bus that manages the complexity of rabbit/sqs/whatever, so you can build simple message handlers and complex orchestration workflows