Advertisers on youtube can't independently use your ip address to target you geographically while you're merely watching youtube, because youtube doesn't send them that information, but youtube, which is part of the google empire, can and does. They can sell targeting to advertisers, including targeting to likely geolocations, but they don't have to do that by ip address.
The video decries people who try to spoof youtube's recommender systems, which are entirely designed to benefit youtube. When youtube tries to keep you watching youtube, they don't care as much what you watch, as they care that you watch, because to them, you are mainly a commodity -- higher viewership allows higher advertising rates, so the most popular vids command the highest ad rates, but if you go somewhere else, youtube doesn't win.
I'm not blaming video producers for getting ad revenue by having advertising interrupting their content, but it puts me off when the ad is introduced as part of the content. It makes it look as if the entire vid is just a vehicle for the ad. VPN purveyors are among the main offenders in this regard.