No. If I have to take up with ads, I want them to fit to the content I'm currently looking at, not stuff I looked at days ago. Paraphrasing another comment (though disagreeing with him), the probability that I'm interested in smart thermostats while I'm looking at content on smart thermostats is vastly larger than the probability of me being interested in jeans while I'm looking at content on smart thermostats.

Unfortunately the dirty secret of ad targeting algorithms is that they don't actually work very well. Computers aren't good at understanding context. It's a hard problem.

Google is better at it then most and, well, you've seen AdSense. It's just OK.

Both consumers and advertisers are mostly aligned in that they want relevant ads. The idea that taking away information about the user is going to somehow make the ads better seems like a stretch.

Well, there is a simple way to solve that: website owner and Ad creator both describe their site/Ad in categories with some hashtags. Just match based on those.