In my opinion, the privacy violation would be taking my biometric data without my consent (e.g. facial geometry, fingerprint, blood, dna/genetics, etc.) While yes my face is public, I’d rather not give them a high-res facial geometry map that gets fast-tracked directly to a database.

Making it harder for them makes them put in the effort to track or profile people which does not eliminate the problem, but does make it more difficult and thus more resource consuming for them, especially if many people do the same