Partly this lets us easily re-route & duplicate telemetry, partly it means changes to backend products in the future won't be a big disruption.
For metrics we're a mostly telegraf->prometheus->grafana mimir shop - telegraf because its rock solid and feature-rich, prometheus because there's no real competition in that tier, and mimir because of scale & self-host options.
Our scale problem means most online pricing calculators generate overflow errors.
Our non-security log destination preference is Loki - for similar reasons to Mimir - though a SIEM it definitely is not.
Tracing to a vendor, but looking to bring that back to grafana Tempo. Product maturity is a long way off commercial APM offerings, but it feels like the feature-set is about 70% there and converging rapidly. Off-the-shelf tracing products have an appealingly low cost of entry, which only briefly defers lock-in & pricing shocks.