The seatbelt comparison is more apt than you probably thought it was. People often don't realize this, but seatbelts not only reduce your chance of dying if you are in an accident. They also can reduce your chances of being in an accident.

If you have to make a sudden swerve to avoid an accident it is easier to maintain control if you are belted in. If you aren't belted in the the swerve can cause your whole upper body to move to the side relative to the steering wheel which can easily interfere with your steering turning a swerve that you would have been able to recover from into a swerve in which you completely lose control.