You’re not totally wrong but some things are not so easily treated as with rescue breathing. This is the same problem with any paralytic agent (e.g. botulism) is that the mechanism of death is suffocation since you can’t breathe. But from a rescue standpoint its really easy to breathe for someone whereas its not easy to stop multiple lacerations leading to exanguination and I think that is the point they were making is that this could be a survivable event if a rescuer is nearby.