There's a particular moment that reveals itself in the contrast between two people in the same room: one absorbed in a phone, the other holding a book. The difference isn't mere preference or generational habit. Physical books create a different cognitive and sensory experience than screens do. They demand a kind of sustained attention that scrolling actively discourages. You can't half-read a book the way you can half-scroll through a feed. The tactile experience matters too, the weight of the pages, the smell of paper, the visual anchor of progress through a spine and pages. What gets lost when reading migrates entirely to screens isn't just nostalgia. It's the architecture of the reading experience itself. Studies have shown comprehension and retention differ between printed and digital text. There's also the social dimension: a person reading a book is doing something visibly different from someone staring at a device. It signals availability for conversation in ways a phone does not. The question isn't whether screens are replacing books, but what specific cognitive and social capacities atrophy when one replaces the other entirely.