I think HN is getting old - nobody has mentioned second screen viewing! imo, youtube videos are getting longer because everyone is just turning stuff on in the background while they're on their phones.

That's what I do. But heck, that's what I've always done. In the 90 and 00s I would have the TV on while I was messing around on the PC, playing my Game Boy, or heck even while doing homework.

My wife and oldest kid who have ADHD are like that. My youngest, myself, and the middle aged kid never have anything on other than what we are actively paying attention to.