It is though. Being an ad supplier is different from being an ad exchange. Or would you describe the New York Times or HBO as "ads businesses"?
Then it went to Netflix where it became a big hit.
There was another show I liked named Ryan Hansen Solves Crimes on Television. They constantly broke the third wall making fun of YouTube Red being confused with some kind of adult content service.
YouTube has its own content while Search ofc doesn't, and its advertising model is different. I wouldn't lump it in with Search. But still, they've decided ads aren't enough and they need YT Premium subscriptions.
https://www.mediagistic.com/blog/how-many-youtube-users-will...
Even HBO is partially an ad company, I imagine their own shows include product placement.