I always found it puzzling that DNS blacklisting for adblocking purposes works at all . I mean I'm not a webdev or anything like that, so what I'm saying might be a bit native, but couldn't you simply serve your ads using the same domain you use for your content? This immediately defeats things like PiHole completely.
It was kind of a revolution to set up these advertising middlemen. Site owners just sign up to show ads and set up their site to load an ad from the ad company's server. Advertisers buy their ad time from the middlemen too. Nobody has to maintain those high-overhead direct relationships. Huge boon for the little-guy sites on both sides. That's the good part. There's plenty of bad parts too, including monopolization of the market, abuse, poor behavior of anti-abuse mechanisms, etc. It's what we've got though, until somebody comes up with something better.