The issue with FLoC is it based on a false premise. Advertising can be successful without needing to build a tracking profile on a person as they traverse multiple websites.

For example if I visit a website that follows trends in computer hardware... advertisers may pay to put ads in this site to PC parts, etc. If I visit a site about popular camping locations.. advertisers can purchase ads that are relevant to camping,gear, travel etc.

The very idea that we need a tracking identity that monitors and identifies behavior from site to site is ridiculous.