The advertisers with deep pockets are fairly less interested in clicks (your conversion rate on an F150 banner ad isn't important to Ford). They are interested

The advertisers with deep pockets are fairly less interested in clicks (your conversion rate on an F150 banner ad isn't important to Ford). They are interested in higher order impacts like brand awareness/preference. They have other ways to measure those things that they've developed over many/many years of not being able to track as well as now.