My mentions are full of bad takes on Mozilla, privacy preserving measurement, and the economics of free software...which I will briefly address, now:
All non-consensual collection of telemetry is unethical.
No you can't just slap a "privacy preserving" label on a mechanism and have it be true.
Even if you could that doesn't bypass the consent obligation.
Yes, Funding free software is complex. developing free software is expensive. I'm a free software dev. I know this. First hand.