The Measurement Problem as Category Error: Ontological Stratification and the Dissolution of the Collapse Demand

The measurement problem persists not because the right collapse mechanism has yet to be found, but because competing frameworks share a structural assumption, ontological flatness, that generates the problem itself. This paper traces the problem to three premises, the flatness assumption being the third: that system and apparatus inhabit a single ontological domain governed by a single dynamical story. The paper rejects that premise, proposing instead that physical reality is ontologically stratified into three distinct layers related by a cross-layer admissibility principle. Within this framework, wavefunction collapse is the perspectival appearance of a cross-layer transition rather than a dynamical event, observers carry no special ontological weight, and the demand for a collapse mechanism is shown to be a category error. The paper then situates the framework against existing interpretations, argues that its consolidation of ontological primitives constitutes genuine explanatory progress, and is explicit about what the framework cannot do. The contribution is an interpretive account of why certain foundational puzzles are consequences of assumptions rather than open questions for physics to resolve, while also identifying empirical consequences that distinguish the framework from standard quantum mechanics and motivate a companion experimental programme.