Earlier quoted context omitted.
many users turn off that telemetry, including me.
It's an interesting question if the percentage of users with telemetry disabled has increased a meaningful amount over time. Mozilla has actually done some work to measure users with telemetry disabled; see the "telemetry coverage" section of https://blog.mozilla.org/data/2018/08/20/effectively-measuri... I'm not sure how frequently they've done this or if any of the data has been made public.
Yes, this was my main thought... It's possible what is being measured is the increased sensitivity of FireFox users to privacy issues, and the increased capabilities Firefox offers to it's users being used, including the option to disable telemetry.
>Mozilla has actually done some work to measure users with telemetry disabled;
That's kinda funny :D it's a meta telemetry telemetry... although as they mention it contains basically no info beyond the fact that telemetry was disabled and is only run on a small sample.
I suppose the only other way would be to attempt to count all the downloads of binary packages through all the Linux repo mirrors, flatpak, snap etc and then finally windows and mac in-browser downloads... which sounds like a nightmare so I can see why no-telemetry telemetry would be attractive.