The design goal is to prevent the natural moment of disengagement. Apps that score high here remove stopping cues: infinite scroll has no page boundary, autoplay queues the next episode before the current one ends, and streak mechanics make stopping feel costly even when the user intended to quit.
B.J. Fogg's persuasive technology model predicts this: the more automatic the behavior, the less conscious decision it requires to continue. Roy Baumeister's ego depletion research adds the other side — willpower is finite, and a session designed to present hundreds of micro-choices steadily draws it down until the choice to stop no longer feels available.