On the contrary, adding just "a few meters of cable" per each critical system, and adding separate sensors instead of using the same critical sensors would greatly increase complexity. Also so really underestimate the cabling and sensor needs for modern requirements.
Having redundant bus and redundant sensors usable by multiple subsystems is a better way.
Well, I have heard of power assist using a single simple potentiometer as a steering wheel position sensor in some really cheap cars... I'm not sure how much of an urban legend that is, but nowadays it surely wouldn't cut it for road permission in the EU.
