As gravel riding takes in a mix of road and off-road miles there will be the likelihood that even the most remote ride will at some point find you on tarmac. Combine that with fact that long miles or bikepacking goes hand in hand with gravel riding means that riding in poor lighting conditions means you may be hard to see to other trail users. If this is the sort of riding you find yourself doing then having secure mounts for lights on your helmet will be a big selling point.
That said, not all riders have the same demands so it isn't going to be a deal-breaker for most.