Motorsport doesn't use airbags and has a steel tubular cage exposed directly to the occupants, the helmet is mostly for protecting from impact with the cage AIUI.

All those grease monkeys driving around with aftermarket cages in their cars and not wearing helmets are actually less safe for it. The last drag strip I was at wouldn't even let you run if you had a cage and no helmet to accompany it.

Airbags and no steel tubes next to your head change the calculus completely.