They're not using "telemetry" as a euphemism for "shipping spyware to end users to record their actions on their own machine", in this case. This appears to be a very fancy log aggregation product that has also eaten logging/tracing related configuration deployment functionality.
It's not even that. It's the interface that other logging/tracing apis can plug into. It's the "SLF4J" of tracing/metrics gathering.
Why is this useful? Because it lets people writing libraries provide the ability for users of their libraries to track performance information without dictating to them what performance tracking tools they should use.
There is the web-packages in Javascript that creates traces for click events etc. but also the track how much time requests took on the client-side. Or render times of the UI e.g. Vue/React components
