Humio is not self-hosted or open source, so not really a fair comparison. It also seems targeted towards operational logs, i.e. system logging, traffic logging, auditing. Not things like data pipelines. Kafka and friends can be used for that kind of log, but they are more like databases; they use the term "log" in the sense of sequential and append-only.

Same goes for Splunk, which does have a self-hosted version, but is extremely expensive, last I checked. The SaaS version is also extremely expensive.