Many of the comments in this thread are talking past each other, by ignoring one side or the other of the cost/benefit balance. It's pointless to shout "But it has benefits, leave it the way it is!" and "But it has costs, eliminate the entire industry!" without engaging with the opposing value set.

I don't think that anyone would disagree with you that true product discovery - educating you about a thing you didn't know about that solves a problem you have - is a benefit of good advertising. Lots of advertising isn't about product discovery, for sure, it's about persuading you to buy a thing you don't want and reminding you about a product you already know about and building an image about the product, and many people want to get off the hedonistic, materialistic treadmill that such persuasion pulls towards, but let's ignore that for now and assume that targeted ads lead to a benefit to the consumer of improved product discovery.

However, I don't think this is a very big benefit, in the real world. I can count maybe 3 things that I've bought in the past year or so where product discovery was important to me, where I was genuinely surprised that the solution was that easy and available. Heck, one was such a big benefit, I'll share: I changed the faucet hardware in my bathroom vanity, but instead of laying on my back and trying to turn the nuts by hand or squeeze in a pair of channel-locks between the sink and the wall, this time I got a targeted ad in my Amazon search results for the faucet advertising a basin wrench, which I didn't know was a thing. That's genuine product discovery, it saved me a little discomfort and a little time, and cost $6. I like the basin wrench, but if targeted ads didn't exist and I could pay a third party to provide me with the same advice I get from targeted ads, I'd value the service at maybe $2/year.

Targeted ads, especially as they're currently implemented, do have a cost to you as a consumer. It's largely invisible to non-technical users, but they do have a significant cost to your privacy. They cost computing cycles and battery life. They cost control of your devices, of your software, and of the websites you browse. Personally, those are pretty significant costs to me. And worst of all, IMO, they have a huge cost in mental fatigue, clamoring for my attention, because for every targeted ad that matches the "has this problem/wants to solve it with this product" combination there are 10,000 that fail one or the other condition. I value these costs pretty high, I bought an SBC just to run PiHole, I pay for Netflix so my TV is ad-free, I buy songs on my phone and wear noise-cancelling headphones in the shop at work so I don't have to listen to the incessant f*ing radio ads. Ugh. And there's little chance I can do anything about the billboards on my commute, though those are contextually targeted to my area rather than invasively targeted. I've probably spent hundreds of dollars avoiding ads, if I could pay someone hundreds more to make the entire industry disappear from my perception I would do so in a heartbeat.

That said, it's not possible to put a number on either the cost or the benefit that's true for everyone. Personally, I feel that those advocating targeted ads generally underestimate how much data is being collected, overestimate the benefits of product discovery, and underestimate the benefits available from alternative, less consumer-costly mechanisms for targeting, like content/context-based targeting.

How many dollars per year do you think the benefits of product discovery, as provided by non-GPDR, non-CCPA, no-holds-barred targeted advertising is worth to you? What price would you put on its costs?