Fingerprinting and connecting to logins has been a thing forever, just look at advertising companies offering cross-device targeting.

Or just how aggressively google wants you to login to youtube these days.

Chrome is also hard-coding exemptions to Google and DoubleClick domains from their so-called privacy features.

This includes things like clearing the cookies leaving Google cookies alone, to sending a header with a browser ID to Google domains. I really doubt Google will get rid of all theirs methods to tie in their scripts on third-party websites to one user ID, as that will greatly reduce the effectiveness of Google Analytics or ReCAPTCHA.

That's very generous. However, with the plethora of browser fingerprinting techniques, cookies today have become almost irrelevant:

https://coveryourtracks.eff.org/

https://scrapebot.com/browser-fingerprinting-techniques/

I wish there was a way to whitelist SOME third party cookies in Safari - the only options seem to be all/none. Many “enterprise” integrations (Box in Salesforce for example) break if third party cookies are blocked.

Maybe Chrome doing it will get them assed to fix it.

Too few.