Site: "This website has no tracking or analytics." Privacy Badger blocked tracking from: googleads.g.doubleclick.net static.doubleclick.net play.google.com www.google.com www.youtube.com Because If you use anything from Google, you will be tracked.
That doesn't happen until you actually attempt to play the video though, right?
Just displaying the page with the embed hits those sites. All in all there were around 20 successful network requests made to load the site. There were another 7 or so requests the Ublock Origin blocked, to play.google.com/log, and then after the page loaded it continues trying those every second or so, although it seems to have slowed down after around 19 but is still ongoing.
It leaves 5 cookies (4 persistent, 1 session) and also looks like it has something in IndexedDB.
Similar with Firefox in a private window except it stores one fewer persistent cookies.
On Safari in a private window it has similar network access, but no cookies.