That’s not what’s happening. The value in a CAN bus control is that you can significantly reduce the wiring requirements.
Old school blinkers and headlights would require separate power wires for every function: Blinker, low beams, high beams. Those separate wires would each be snaked through long wiring harnesses back to relays somewhere else in a central location.
With CAN, you can run a single large gauge power and ground pair and use the CAN bus to tell the remote module what to do with tiny signal wires. It may not sound like a big deal, but cars have a lot of electronic pieces all over. Simplifying wiring can add up to a significant weight and cost reduction. You now also have the ability to add more monitoring, such as simple sensors to detect when a bulb has failed
Vehicle manufacturing is ruthlessly optimized. Vehicle manufacturers wouldn’t add complexity to common systems if it didn’t pay off.