Seems like the the key pillars are: freshness, volume, schema, distribution, and lineage.

Makes more sense this way, I think...

If you think about metrics, traces, and logs (software observability pillars) as three distinct things, it's hard to view metadata separate from metadata, lineage, or logs. Metadata is kind of the glue that holds everything together.

This article has more relevant sources, IMO, even if it is from a SaaS vendor.

https://www.montecarlodata.com/blog-what-is-data-observabili...