Maybe there's too many advertisements and the product (sports action) is too watered down. I think there's been a bubble in timeouts and video reviews and commercial breaks and something is bound to cave in. I was at a CFL game for the first time in years and it was remarkable to see that every one of my group of 20 friends drifted on home well before the end of what was a very close game. It just takes too damn long. And I was following the score in an NBA playoff game while i was busy doing something at home, and the last 10 seconds of clock must have taken a full 20 minutes to run out. It wasn't suspenseful it was like ... hey I've got a lot of other things to do, get on with it.
I'm a pretty casual sports fan but it seems to me that a business case risking billions of dollars on the assumption that North Americans are going to stare at their phones for three hours of ads to see less than 60 minutes of actual sports action is a sucker's bet.