Just last night my wife asked how I can play a game (Path of Exile) and watch YouTube on my other screen. It was a little hard to explain but I mentioned I tend to watch videos I don't really need to look at (in this case it was just the relaxing tones of LockPickingLawyer) and I was kind of playing in a flow state in PoE so it didn't need my full attention.
What is really concerning is when I am watching something I actually want to pay full attention to on YouTube/Netflix, and I find myself opening a fresh tab to load up a second video before catching myself and realising it's ridiculous listening to two videos at once talking over each other. Putting the speed up to 1.75x or so helps with this if it suits the topic. In fact that was one habit I built during COVID, and going from YouTube videos at 1.75x to voice meetings with slow-talkers back in the office I found myself reaching for a speed button that didn't exist.