Comment by SquareWheel

It is true that the CMA is concerned with the new API proposals within the Privacy Sandbox such as Topics. However, this is from an anti-competitive angle, rather than privacy. Their goal is to ensure market fairness.

As part of that same process, they have put considerable friction in place for removing third-party cookies. They've deemed that the removal of third-party cookies could give Google an unfair market advantage, and that is why they're concerned with finding an alternative solution to replace them. This has been a very slow process, and involves many discussions and debates with regulators. That has had significant influence on the design of the Topics API.

To provide a more direct example, the CMA have also put specific stalls into the deprecation process, such as the standstill period invoked last year:

> The CMA will start a formal review of Google’s plan to deprecate cookies and Chrome’s Privacy Sandbox replacements once Google triggers a 60-day standstill period, likely at the beginning of the third quarter. During this standstill, the tech giant is forbidden to put in motion any deprecation procedures on Chrome. ... If they can’t reach an agreement, the 60-day standstill period will become 120 days.

https://www.adweek.com/programmatic/the-cma-is-prepared-to-d...

To put it simply, third-party cookies would have been dead and buried long ago if this dispute were not happening. It may be possible for Google to remove third-party cookies without a replacement, but they'd have be risking a significant lawsuit and contravention of UK authority by doing so.