They should’ve started with user choice as the first milestone when it was originally announced. Similar to Apple’s app tracking. Or just get rid of cookies and let ad tech be less invasive.
They tried to get rid of third-party cookies and regulators wouldn't let them do that.
You would have to break up Google in order for them not to have a a insane market advantage if they got rid of 3pc. Google would still have access to all their consumer markets, google analytics, etc, and everyone else would have to do business with google or go out of business.
Market regulators don't care about privacy or data safety, they care about whether your local ad agency can make as much money as Google can doing the same stuff.
Cookies are cross-platform, and transparent. I can see and edit and erase my cookies locally at any time.
I would rather tighten the rules around privacy and keep cookies around rather than the opposite.