So CD player can instead spam all other subsystems? And going to PtP links is distinctly a step back.
Never mind that you now need a complex IP stack capable of supporting PKI on each freaking sensor. If that's not a definition of madness, then I don't know what is.
CAN bus is fine for what it does. It's GREAT. The problem is, it's an internal bus that's being abused to interface with external systems.
Adding PKI to each sensor is like adding PKI to your hard drive to fight against computer viruses.