Case's addiction isn't to the matrix as fantasy—it's to the matrix as a system where input produces output, where action has legible consequence, where the scope of possible outcomes matches the scope of human ambition.
The physical world offers him money, allies, a body that works, yet none of it satisfies because money is finite, allies have agendas, and a body gets tired.
The matrix offers something cheaper and more addictive: a space where his skill translates directly into being. He moves through cyberspace the way a god moves through a universe he built himself.
When Molly asks why he keeps jacking in even after Wintermute fixes his nervous system, Case has no answer because the answer is structural, not psychological. The matrix isn't better than reality—it's more responsive, responding immediately and scaling with your input in ways reality never does, talking back slowly and in ways that don't care about your effort. Gibson understood something the Valley wouldn't figure out until the algorithmic feed: the addiction isn't to content, it's to a world that has been engineered to never tell you no.
Case returns to the matrix not because he's broken but because he's rational—the real world is a closed system with fixed walls, while cyberspace is infinite optionality with no friction, and once you've felt that difference in your nervous system, the finite world doesn't just feel small, it feels hostile.
Read the scene where Case jacks in after Wintermute patches his system (Chapter 15) immediately after reading a day's worth of algorithmic feeds on any platform—notice how your attention moves in the same direction, toward the space that responds most immediately to your input.
Bruce Sterling's foreword to the 2003 Ace edition argues Gibson was writing about information ecology, not technology—find the specific passage where Sterling connects Case's jacking-in to the structure of attention itself, not the content Case encounters.