A counterexample is not a valid refutation of the general point. It can be both true that Google will deanonymize you, given the chance, and that anonymous attestation is possible.
Having thought about ads, what is the ideal feedback info channel loop from manufacturers to consumers? How best to distribute the information of who can manufacture what at what cost/price and what does it do and when is it appropriate for consumers to receive or pull info from where? And if it ends up being a monopoly of 1 centralized system how do you allow for a competitor to break through without ads?