Well that depends on each particular metric. E.g. if we don’t collect gnome-control-center panel usage data, then the GNOME design team has less information to use to make design improvements. They’ve been trying to move frequently-requested settings from Tweaks into gnome-control-center but have been having trouble because user studies indicate users are already having difficultly navigating the high number of settings. So some consolidation of panels is needed. But (a) what settings to consolidate or remove? how do we decide without usage metrics? And (b) how do we know that the design changes were successful after they have been implemented? With respect to (a) specifically, I’ve seen proposals to remove most of the Sharing settings. So let’s say those settings are at risk without telemetry. (I don’t remember offhand if the Sharing settings are actually still at risk, but it’s a real non-hypothetical example of a design change where telemetry would be helpful.)
Sticking with the example of gnome-control-center panels: how else would you gather panel usage data from a representative sample of users? (i.e., not from users who choose to respond to a survey, since those users are not going to be representative of typical Fedora users.)