The ad industry has known about their fraud problem for years, at least since 2015--and they did little to nothing about it. I don't have much sympathy for them.
If the threat you're seeking to mitigate is malicious ads ("malvertisements,") then you could easily pass that burden to the ad networks themselves. I think it's extraordinarily rare for a website to sell "banner space" instead of just throwing in an AdSense snippet or similar.
"They don't have sarcasm on Betelgeuse, and Ford Prefect often failed to notice it unless he was concentrating."
-- Douglas Adams
It turns out that sarcasm is sometimes not obvious to everyone. My apologies.
You are correct. They cannot be trusted. The entire history of advertising and advertisers is evidence that they cannot be trusted. They cannot be trusted to self-regulate, to follow voluntary codes, or even to form an industry regulating body (sorry, UK, you know it's true).
And yes, Google is an advertising agency... which spends up to $20MM a year on federal lobbying.
