Dude, they ARE the advertiser. That’s Google’s main business. They have no incentive to export ANY of your account data to 3rd parties. Business tell them what groups of people to advertise to, and their systems handle the rest. They’re open about how it all works.

As someone who’s actually worked in this industry, your data isn’t enough to pay for video hosting services to the scale youtube provides. Youtube makes up a significant chunk of all network traffic in the world. It costs money.