SQS is simple queueing service in AWS. It's ok, guarantees at least one time delivery, but I am not sure how useful it is for large volumes of messages (by this I just mean that we use it for low volume messages and I don't have experience when using larger volumes).
SQS is fantastic at exceptionally high total volumes of messages - you probably can't saturate it. But it's not great for streaming a list of ordered messages. SQS has a FIFO mode but performance will never be what you can get out of Kafka.
Also, SQS isn't pub/sub. Kafka and SQS really have very different use cases.
