I totally appreciate the desire not to want an advertising profile build for you at all! I think that in practice, interest-based-advertising is going to happen, and I think if chrome can provide a way for it to be done without involving so many sketchy third-parties then I'm for that.

I don't know a huge amount about the wider ecosystem here, but I can imagine that if chrome were to disable third-party cookies without providing an alternative, then advertisers will go to fairly great lengths to fingerprint you to build a profile.

Right now my guess is that Firefox users benefit from the fact that it's probably not worth investing all that much in alternative tracking techniques since you capture the vast majority of people with techniques which work in chromium browsers.

Again, I really don't know that much about all this, but my feeling is that this is moving in the right direction, even if it's not the solution I'd ultimately prefer as an individual user.