Do you know how the web works? When you go to a website, you are making a request to someone else's servers. If you don't like what they are serving, then stop going there. Vote with your attention. I have stopped visiting places like BusinessInsider due to their adblock-block and free-quota walls. They no longer get traffic from me.
> If someone voluntarily exposes themselves to ads, then yes, those ads are probably valuable. But that does not happen.
It does happen, it's called "coupons". There are plenty of coupon aggregators that people use all the time: RetailMeNot, Groupon, Ebates, Slickdeals.
Trying != succeeding. If someone applies force, it rarely means you cannot choose not to comply. But you'll suffer from the consequences.
> It does happen, it's called "coupons".
Not really. The value of coupons is that you get discounts, not that they advertise something. Classifieds are a better example.
(Arguably we would better off if coupons did not exist and companies just set proper prices to begin with, but that's beside the point)
Either way, even if valuable ads exist, advertising as a whole still destroys value because the vast majority of ads are destructive.