I don't quite get it, what does this do?

The readme says absolutely nothing (e.g. "The OpenTelemetry specification describes the cross-language requirements and expectations for all OpenTelemetry implementations." and goes on to describe how to submit changes or on which proprietary platform meeting minutes can be found) and the Overview document goes into depths about terminology (what a trace is, what a span within a trace is, how to link spans, etc.).

Nowhere does it say if this is supposed to, for example, replace proprietary crash reporting in apps so that we can know what is being reported back to the mothership, or if this is something completely different.