I find this ironic. I don't wear a helmet, but find myself defending the claim that they help prevent, or reduce the likelihood, and severity of concussion (aka TBI), while you who wears a helmet says that claim is wrong.

Without being accusatory, might I ask why you wear a helmet, if not to help prevent TBI?

OTOH- I do support the notion that avoiding crashes in the first place is the best way to reduce injuries, including head injuries.