It's yet another scheme to gather data about Chrome users for the benefit of advertisers. Aside from the fundamental problems with that whole idea which people most often point to, it's also underhanded in a way that cookies, tracking scripts, and browser fingerprinting aren't: It's code that's built in to the web browser itself which exists for no purpose other than to act directly against the interests of its users. It may be the first time that's happened in such an obvious and unambiguous way.

Federated learning as a machine learning topic is unrelated to floc afaict.

The issue I have with things like FloC and the topics API are that they are attempts to keep the cash flowing at Google before disabling 3rd party cookies, when it seems obvious that the time to disable 3rd party cookies is now.

Vivaldi removed it from Chromium more than 2 years ago, just like before and after all of Google's other dirty tricks to track and profile users. No serious browser, Vivaldi, Firefox or Mozilla forks, will enter the Google game.

@tester1121 so you can rest assured (as long as you don't use Chrome or EDGE or search with Google)

https://vivaldi.com/blog/no-google-vivaldi-users-will-not-get-floced/

All you need to know is its a proposal by Google for a new web standard. Enough said.

from my experience the description of what this is by google itself is confusing and/or misleading, so be wary

I think this is a pretty good breakdown and worth a read. Some key takeaways are that with FLoC Google would be able to track visitors to your website even if you were not using Google Analytics, and that the mechanism is built-in the Chrome browser so entirely controlled by Google.

Here is a related article about Topics, the FLoC replacement.