Great list. One "tool" I'd add to this stack (conceptually) is "Upstream Observability."

We recently learned this the hard way. Launched a new Teams app, and our main dashboard reported a catastrophe: 1 visitor, 1 pageview, total failure.

But we dug into the raw logs (upstream of the dash), and the reality was 121 unique visitors and a 31.4% share rate. The pipeline was fine; the visualization was lying.

If we had trusted the "single pane of glass" without validating the ingestion, we would have scrapped a successful product. The tools are amazing, but only if the data feeding them is verified first. Log validation > Dashboard aesthetics.