Be careful what you wish for. This TED talk[0] on persuasion architectures brings up some interesting moral arguments against this idea. If we generally accept that ad conversion is a metric of an ad's success, how do we handle the situation where people that are susceptible to addictive behaviors like gambling and compulsive shopping are exposed to ads that exploit their condition? Data-driven advertising systems are built particularly well to find and exploit these kinds of people. We already see this a lot in the scam call/email world. Once you fall for one, the amount of inbound traffic you receive from scammers increases dramatically.
Ads like that used to be common. By your description, it sounds like they died out on their own.
A well targeted ad doesn't need to serve you well, it just needs to convince you to buy; I have a lot of faith in myself and I'd say those are often the same thing, but experiences may differ.
Anecdotally of course, as one of those tech-folks who's got nothing against good and relevant ads.