Not all simple polytopes are incribable, e.g. the dual of the cyclic polytope $C_4(8)$ is simple and not inscribable, as shown recently in [*Combinatorial Inscribability Obstructions for Higher-Dimensional Polytopes* by Doolittle, Labbé, Lange, Sinn, Spreer and Ziegler][1] [1]: https://arxiv.org/abs/1910.05241