Seems like you’re right. I just noticed that when you right click the video -> Stats for Nerds, there’s “volume/normalized” and when it says 83%, pulseaudio will also be 83%.

I guess there might be some way to tell pulseaudio to ignore the volume of the video player

Imagine there’s a leap year and suddenly the year is three times as long

Kinda. If I move the volume slider of the YouTube video player it also moves in pavucontrol automatically. But when I move it to 100% in YouTube it’s only 83% in pavucontol

I had the same idea. Audio normalization is off in the youtube player. Maybe there’s another normalization going on in the pipeline