I have a lot of questions about your comment. Forgive me if I misinterpreted what you meant. Also, I’m not the person you responded to, just FYI.

Google wants to get rid of a large part of their data gathering system because collecting all of that data is a huge business risk

Gathering data on people is Google’s business, so what do you mean by this? Topics is still going to gather information; if anything, it accelerates data harvesting, because all of that tracking information has to be decoded at a hub – which, of course, will be Google. So what do you mean by that statement?

don’t really get why it’s “Tracking Cookies 2.0”. Data is stored and analysed locally

… and then shared with the websites you visit. It doesn’t stop web sites from profiling browsers, and the cohort can be used to drastically reduce the set of possible users and pinpont an individual. How is that not “tracking cookies 2.0?” Any information a tracker can get about you, including your cohort ID, improves identification algorithm results.

It’s even worse than cookies, because fundamentally it’s profiling. And when the data leaks happen, it’ll be lists of people lumped together however tenuously with other people, regardless of their real interest. If you thought the Ashly Madison breach wreaked marital havok, wait until the first data breach where perfectly innocent people are lumped into a cohort that also happens to strongly feature visitors to Grindr.

We agree that Google is a wellspring of horribly invasive, privacy-violating technologies; I just don’t understand why you feel this one is different, or overstated. The strong (and technical) responses from Mozilla and the EFF are a good bellweather for things like this.