[imtringued]

>Nothing short of personalized age verification will work.

Specifically, daily personalized age verification by the specific app/website, not by a third party.

>The only way this can go wrong is if the client sites collude and publish their visitor logs and then the government can do the legwork to identify you.

Well, the government has the right to request proof that the company in question is properly conducting the age verification process. This means that the companies performing age verification will keep your personally identifying information (PII) and maintain an association between your PII and your account/activity on the platform.

On a different note, the government has the right to gather evidence of criminal activity, where the definition of "criminal" is under their discretion and if there happens to be a convenient stash of information that can be linked to your person, that's just a happy coincidence.