There was a tender issued by TDF for usability metrics collection, though it was never worked on from what i know.
Created this google doc with details on what data should be collected for usage metrics.
I like the idea of metrics but we currently don't collect them we probably should remove the code. A relatively easy change might be deleting the checkbox to activate it which declutters the settings UI at least a tiny bit.
The usage-data collection code was removed and there are no plans to add privacy-invasive telemetry.