Same. Kafka might be better for larger datasets/throughput but a much harder to maintain and manage. Redis is much simpler if you know you aren’t going to scale that much
It's less about scale and more about availability - by the time I've set up a 3 Redis + 3 sentinel cluster it doesn't look operationally too different in complexity than a small Kafka cluster (and more complex once KRaft is ready). But a single non-HA Redis is way easier. (But if I don't need HA - a single memcache is easier yet...)