Quote:Mozilla Firefox is one of the few web browsers out there that gives users and system administrators options to turn off Telemetry.
Telemetry, which Mozilla introduced in Firefox 7 back in 2011, provides data to Mozilla which the organization uses to refine its products.
While that is often beneficial to users, for instance when issues are detected and fixed, it has also been used in the past to justify the removal of features from Firefox. The removal of features based on Telemetry led to my suggestion in 2013 to keep Telemetry enabled to make "your voice" count.

Full reading: https://www.ghacks.net/2018/09/21/mozilla-wants-to-estimate-firefoxs-telemetry-off-population/