Example - mystery runtime, while inconvenient to someone in a hurry, is useful in keeping suspense or surprise. It's kind of hard to convince a reader that the hero is at risk of dying when there's obviously 2/3rds of a book left.
Do the pros outweigh the cons? Probably not. Should it at least be an option on modern video platforms? Maybe. But the important thing to me, is that we remember how such a thing changes the viewing experience before every film for the rest of time comes with a progress meter attached.