AI is now embedded in classrooms at every level, and the early returns split cleanly along a single axis: how students actually use the tools. The headline finding is stark — faster homework completion paired with declining exam performance — which points to a substitution effect rather than an augmentation one. Students are outsourcing the cognitive work that homework was designed to produce. The mechanism is straightforward. Homework exists not as a product but as a process — the struggle of working through problems builds the neural pathways that exam performance depends on. When AI completes the struggle, the student gets a finished assignment but misses the learning. It is the educational equivalent of having someone else do your reps at the gym and wondering why you are not getting stronger. This is not a technology problem. It is an incentive design problem. Students face competing pressures: grades reward completed assignments, but learning requires effortful engagement. AI tools make it trivially easy to optimize for the first at the expense of the second. The system rewards the output while the student loses the process. The impact splits along usage patterns. Students who use AI as a tutor — asking it to explain concepts, check reasoning, generate practice problems — appear to benefit. Students who use it as a completion engine — paste the prompt, copy the output — degrade their own learning. The technology is identical; the pedagogical outcome is opposite. Institutions face a structural lag. Assessment systems were designed for a world where completing homework required engagement with the material. That assumption is now broken. Schools that do not redesign assessment around demonstrated understanding rather than assignment completion will produce graduates with polished transcripts and hollow competencies. The extraction pattern is clear: AI companies capture engagement and data, students capture short-term convenience, and the long-term cost — diminished human capital — is borne by the students themselves, their future employers, and the broader economy. The people who bear the cost are the same people making the choice, but they bear it years later when the bill comes due. The question is not whether AI belongs in education. It is whether education systems can redesign incentives fast enough to channel AI toward augmentation rather than substitution. The technology is moving at software speed; institutional reform moves at bureaucratic speed. That gap is where learning goes to die.