The problem is not ads. The problem is SPAM.
There are plenty of legitimately well-intentioned ads that can connect someone who needs a good/service with someone that supplies it and everyone wins.
The problem is that we use a nearly totally free unregulated market where anyone can advertise anything anywhere.
edit: I'm not saying we should necessarily try to optimize for good ads over bad ads or even assuming that is possible. I would settle for just somehow reducing the total volume of ads to help make email, snail main, voice mail, and other methods of communication more usable.