"And commercial breaks can be quite useful for giving you a chance to get a snack (for example) in the middle of a programme."

No kidding! ;-) I bet that the connection between regular commercial interruptions and snacking has become a very significant factor in the sharp rise of obesity in the North American population during the last few decades.

Whereas...if you know ahead of time that a show is going to play straight through, and you're planning to watch it, well then if you really want to eat while you're watching it you just plan ahead and have your snacks ready at the start....like when you go to a movie and buy some popcorn and a drink. That is NOT a major challenge! ;-)