Smart polymers respond to environmental factors such as change in temperature, pH, or solvent. An example is the nonlinear dependence of solubility on the solvent composition where a mixture of two good solvents yield a poor one. This phenomenon is known as cononsolvency and it has been known for over 30 years. However, there is still no consensus over its molecular mechanism. A number of models have been suggested, some of which outright contradict with each other. The task to identify the responsible factors is impeded by a number of issues. For one, the experimental studies are mostly limited to larger scales where direct observation of the responsible molecular interactions is not easy. Although computational simulations allow identifying molecular interactions, they face the tremendous task of properly sampling highly flexible chains at large resolutions. Furthermore the subtle interplay between the enthalpic and entropic contributions and the shortcomings of the available methods to measure these components with high accuracy increases the difficulty of the task. The factors above prevent an easy setup to explain the underlying mechanism and therefore leads to a disagreement between the community.