We've had "small-scale" Kafka for a long time. It's an append-only log, and there are a number of ways to implement it, but it's essentially that.

The thing that makes Kafka interesting is the technique of operating from a linux disk write-buffer. That's the trick that makes it fast and scale to huge volumes. But if you don't have the scale, you can stand up a table, or RabbitMQ, or anything that manages append-only ordered log entries. There doesn't need to be a new thing... Kafka was the new thing.