Look into Pulsar, it can function as a message queue or pub/sub like Kafka. By default it only retains non-acked messages, multiple subscription modes, can use

Look into Pulsar, it can function as a message queue or pub/sub like Kafka. By default it only retains non-acked messages, multiple subscription modes, can use non-persistent messaging, dead letter queue, scheduled delivery, can use Pulsar Functions to implement custom routing etc. Scales like Kafka (probably better) and has cluster replication built in.