By the time Toyota was in the news in 2011 for potential throttle sticking problems that killed people, it was typical for even economy cars to have something like 30 ECUs controlling different things, with each ECU and its associated sensors requiring multiple chips.

Yep. My 2008 Toyota Sienna has many controllers. Each door has its own dedicated controller, and there are digital servos with their own controllers inside the sliding doors that handle remote operation.