Usually people who buy ads pay for clicks on those ads.

So, the idea is to register a click on the ad, which makes the business pay the ad agency it’s commission, but not actually visit or look at their website, which is the whole point of buying an ad.

If businesses see that paying ad agencies brings little to no actual customers, they stop buying ads. One can only hope.

They also have a paper addressing many of your concerns.
https://ceur-ws.org/Vol-1873/IWPE17_paper_23.pdf

That said, I don’t use it myself, mostly because of bandwidth and processing cost reasons. I also don’t care about it that much. Ads suck, but I barely see any of them due to my browsing habits.