My guess is that the vast majority of people wouldn't pay. Firstly, because it's notoriously difficult to get people to pay for something that used to be free.

My guess is that the vast majority of people wouldn't pay. Firstly, because it's notoriously difficult to get people to pay for something that used to be free. Lack of tracking and respect for privacy is not something most people would recognize as an obvious upgrade - hence the need for legislation in the first place. So the public will see it as paying for the exact thing that used to be free, and just won't do it. If Google won't find a loophole to bring marketing, paid results or some other monetization back in such a legislative environment, someone else will. You'll end up with something that's won't necessarily be better for consumers than the advertising model.