Why don't ad based agencies allow users to opt out at 2x whatever they would have earned from the ads? Seems to benefit all involved, the content providers get

Why don't ad based agencies allow users to opt out at 2x whatever they would have earned from the ads? Seems to benefit all involved, the content providers get the money, the users who are willing to pay a few $0.01 don't see ads, and the ad agency makes more money. Doubly so because the remaining ads will be worth more.