You're completely clueless, just stop talking.
First, the "ad network" in this case and the "publisher" are the same thing. Second, nearly all of effective modern performance ad buys on the major publishers (Meta/Google) outsource most of the targeting to the publishers via tools like lookalike audiences (Meta) or dynamic search ads (Google), all of which are powered by user data. In fact, the publisher's loss of performance data via IDFA was the entire reason why losing IDFA was so bad for Meta. It wasn't that the buyers couldn't close the loop on who was converting (they could), it was that the publisher couldn't close the loop on who was converting (super important for targeting). The idea that buyers drive conversion and the publishers have not much to do with is wrong. It's blatantly obvious you have no direct experience in this area, and no idea what you're talking about.
Sources:
- Spent over $100m on performance ads
- Started and ran an ad attribution company
- Ran the team that built the Reddit ads platform and know how hard it is to make a performance ads platform work as well as Meta or Google (basically impossible)
These ad networks own the market because they're the only suppliers of digital ad space with enough billboards to meet the massive demand; that's no small feat. And yes, they do have very far reaching tendrils to determine attribution which is also technically impressive but that's also not without a sea of muddy data especially when it comes to VTA.
Google and Meta aren't magic and you're giving them far far too much credit for what are really your own (or the agency you paid) successful ad campaigns because you did all the work.