Advertisers don't care and have never worried about this. It's the adtech supply chain, and the publishers who get paid that worry about the revenue and targeting.
Depends on the advertiser! Big brand who mostly wants to reach everyone in a geographic area? Targeting doesn't matter. Retailer that wants to bring someone back in to complete a purchase? Without targeting they won't buy ads at all.
You suggest this as if the majority of ad spending comes from small businesses trying to retarget their customers; when the vast, vast majority of ad spending comes from big brands; and your mom and pop business isn't running a sophisticated ad targeting campaign.
(Disclosure: I work on ads at Google)