If you are using this sort of redis queue (https://redis.io/glossary/redis-queue/) with PUSH/POP vs fan-out you're working on a very different sort of problem than what Kafka is built for.

Like the article says, fan-out is a key design characteristic. There are "redis streams" now but they didn't exist back then. The durability story and cluster stories aren't as good either, I believe, so they can probably take you so far but won't be as generally suitable depending on where your system goes in the future. There are also things like RedPanda that speak Kafka w/o the Java.

However, if you CAN run on a single node w/o worrying about partitioning, you should do that as long as you can get away with it. Once you add multiple partitions ordering becomes hard to reason about and while there are things like message keys to address that, they have limitations and can lead to hotspotting and scaling bottlenecks.

But the push/pop based systems also aren't going to give you at-least-once guarantees (looks like Redis at least has a "pop+push" thing to move to a DIFFERENT list that a single consumer would manage but that seems like it gets hairy for scaling out even a little bit...).