Placeiq is a third party data vendor that usually integrates with a demand side platform (dsp) like google’s dv360, the trade desk, xandr, etc. But you can use their data in other ways outside of dsps for things like measurement or maybe whatever the gov is doing.

Ad-tech is not only "ad platforms"

It sounds like you just aren't aware of how deep a rabbit-hole the ad-tech space is. Google gets to be the relatively-clean "platform" at the top, but they don't exist independently of the rest of the industry.