let’s be clear: cookies were not supposed to enable third-party tracking, and browsers were supposed to block third-party cookies. We know this because the authors of the original cookie technical specification said so (RFC 2109, Section 4.3.5).
First, large scale blocking of cookies undermine people’s privacy by encouraging opaque techniques such as fingerprinting.
Second, protecting consumer privacy is not like protecting security—just because a clever circumvention is technically possible does not mean it will be widely deployed
Third, even if a large-scale shift to fingerprinting is inevitable (which it isn’t), cookie blocking still provides meaningful protection against third parties that stick with conventional tracking cookies. That’s better than the defeatist approach that Google is proposing.