Granted it doesn't happen often, if you plan correctly, but the possibility of going wrong in the partitioning and replication makes updates and upgrades nightmare fuel.
Then we settled into an era where server rooms grew and workloads demanded horizontal scaling and for the high profile users running an odd number of processes was a rounding error and we just stopped doing it.
But we also see this issue re-emerge with dev sandboxes. Running three copies of Kafka, Redis, Consul, Mongo, or god forbid all four, is just a lot for one laptop, and 50% more EC2 instances if you spin it up in the Cloud, one cluster per dev.
I don’t know much Kafka, so I’ll stick with Consul as a mental exercise. If you take something like consul, the voting logic should be pretty well contained. It’s the logic for catching up a restarted node and serving the data that’s the complex part.