Against probability: A quantum state is more than a list of probability distributions

The state $\rho$ of a quantum system can be represented by a vector ${\mathbf{P}}_{\mathcal{M}}(\rho )$ of outcome probabilities for a set of measurements $\mathcal{M}$. Such representations appear throughout physics, for example, in quantum field theory via correlation functions and in quantum foundations within generalized probabilistic frameworks. In this work, we identify an unavoidable tension: to enable operationally meaningful statements, the map $\rho \mapsto {\mathbf{P}}_{\mathcal{M}}(\rho )$ must be topologically robust $\text{unicode}x2013$ preserving the notion of closeness between states. Yet, a probability representation that is topologically robust cannot simultaneously retain other essential structure, such as the subsystem structure.