I clicked on this with a rebuttal already half-written in my head, but (after skimming the CTO's post and then reading the detailed explanation of PPA[0]) I'll admit that I jumped the gun on assuming that PPA was just the latest name for storing an ad id. The idea behind it (that you have to give the advertisers an anonymous way to measure conversions to have a shot at getting them to give up tying your traffic back to your identity) is reasonable, and the implementation doesn't look crazy.

There's details I don't understand yet and I'd like to see someone smarter than me critique the details, but for now I'll put my money where my mouth is by going in to Settings and re-enabling it.

0: https://github.com/mozilla/explainers/tree/main/ppa-experime...