Actually, I disagree. The XM/605 wiring across the dash is a massive swag of conductors, but you learn to get into diagnosis pretty fast by colour and likely gauge. With CANBUS arrangements, a strained or chafed connector (they are still just crimps) can give dodgy signals across everything and not be very easy to diagnose.
Also, in vehicle repair - I can put a feed into any circuit of a non-multiplexed car and do something like operate a seat or window while everything else is out of action.
Progress is slow but steady:
