I'm currently at a small ad tech firm and while I can't speak for other outfits, we
definitely are extra careful about respecting user consent indicators. Because we are small, it's not easy to do this, because there are many possible ways for users to "reject". This includes situations that merely
imply non-consent due to inaction, rather than active non-consent like a reject cookie indicator, or living in a jurisdiction that makes non-consent automatic (as it should be!). Many of the "reject cookies" tools are especially useful because even if a
website doesn't respect your choice (and therefore tries to send data to us) your
browser can still tell us if you are non-consenting. This means it's easier for us to notice non-consent and drop the data as soon as possible, before any logging or analysis can occur.
We do not materially benefit from this in any way, nor do we market it. I am not a spokesperson for my company nor do I want to be publicly identified with it. I'm advocating here because you said "not a chance" but there is a chance.
It's not just that we are worried about some sort of regulatory enforcement, either, although existence of such regulations does help convince the less scrupulous people from pursuing a bad path.
The free internet is built on ads. I still believe in the free internet. I still think we can make it work. I welcome regulation and regulatory enforcement even though it's hard for a small outfit like us, because it reduces the chances that our ad tech has to compete with less scrupulous people. I think we've survived as a small outfit since roughly the dotcom era because we've tried to be good stewards. People wouldn't need uBlock if there was better regulation/enforcement, and companies like mine, who are trying to do the right thing (even as we operate in the loathed ad space), would benefit.
I'm worried about AI on this front because it means in the future your ads will be served up to you out of a black box instead of out in the open where we can all inspect who is trying to get what from us (and block bad parties via eg uBlock), and, to a degree, who is trying to shove what down our throats.