[deepsun]

Very different tools, applications almost don't intersect actually.

ClickHouse is an analytical database (for events). Yes, you can do metrics in there (or PostgreSQL for that matter). Observability has their own needs, so specialized solutions work better, more integrations and out-of-the box tooling already provided.

With generic databases it's more like a constructor that you'd need to develop a lot to become workable. For example, let's say you have 50m active time series, with 1%/hour churn rate. What would be the database structure in ClickHouse? (my answer is that I don't know. I know mostly VictoriaMetrics, and there's no such question there, the structure is already implemented).