My partner worked (briefly) at an adtech firm. Her comment is always the same: "it is SO much creepier and (more!) pervasive than you think".
@mwl I've used an ad blocker for so many years that when I use a computer without one I'm stunned by how unusable so many we'd sites are.
We're also trapped on an ancient 5.5 Mbps ADSL line and on a begging list to be upgraded to fibre before ADSL is turned off nationwide in 2030. Ads slow browsing down to a crawl if you don't block them and eat CPU cycles like there is no tomorrow...
@mwl Probably a site that also wants you to accept cookies from their 1573 partners.
(no hyperbole)