I’m curious what electronic throttle’s redundancy is? I have been in automotive parts and repair almost 15 years, and drive by wire has no redundancy. If that module goes bad, or connection corrodes, you are dead in the water. Braking has always been hydraulic based but with electric actuators for ABS, so I kinda see your point of redundancy there. Steering has to be mechanical, but Lexus and Mercedes have been chipping away at that for a decade, and they are asking for no mechanical fallback, as it would hurt the user experience.