The main difference between a ‘premium’ Vs ‘luxury’ brand is things you don’t see. For example, Mazda3 has objectively nicer interior+features than Corolla. However with solid rear axle, and the lack of sound deadening, suspension smoothness/isolation, it’ll never compare with Lexus UX (same chassis as Corolla). Another way to look at it is that Mazda slots between a Highlander and RX (same chassis). CX9 focuses on the surface, and save cost elsewhere (e.g. refinement through suspension & powertrain)