Setting aside whether FLoC is private enough, how can you say it is not more private? Today, with third party cookies, many companies have almost your entire browsing history through a combination of direct tracking and cookie matching.
With FLoC this information stays on your device, and only a summary is made available to sites.
I'm not sure which part of the post you're referring to when you say that FLoC isn't more private than the status quo; is it the "FLoC will expose your data. More than ever." section? That has "Now every website will get to see an ID that was generated from your behaviour on every other website", but this is not what Chrome has said:
"Websites can exclude a page from the FLoC calculation by setting a Permissions-Policy header interest-cohort=() for that page. For pages that haven't been excluded, a page visit will be included in the browser's FLoC calculation if document.interestCohort() is used on the page. During the current FLoC origin trial, a page will also be included in the calculation if Chrome detects that the page loads ads or ads-related resources." -- https://web.dev/floc/#do-websites-have-to-participate-and-sh...
Suddenly the tracking includes all sites and pages. That is not an improvement. Having an opt out or even an opt in is not the solution here. We have all seen how that works.
The tracking just has to stop. Google can generate plenty of revenue without tracking us. They were in fact making plenty before they moved from context sensitive ads to surveillance-based ads.