1. There is an erosion of physical limitations on how much time you can spend on an activity on an "item". A comic book has fixed no. of pages, once you have finished, you need to get another physical comic book. It doesn't automagically keep adding pages as you keep turning.
2. Deliberate algorithm driven strategies to increase "engagement": the content of the comic book is fixed - you either like it or you don't. It doesn't change the content on the fly based on which turn of events you prefer. Offline video games had more "engagement" but it still was limited by the inbuilt branching of possibilities (which still could be a lot depending on the cleverness of the algorithm/engine - that is why people spent hundreds and thousands of hours on them even without them being MMPROGs). With the current set, the entire thing is driven to reel you in right from the get-go and keep you hooked as long as possible. That surely can't be a good thing for your health.