I'm not sure that's the intended purpose for barrel notches. I rather think it's to gain more positive control for the slipping rather than relying on friction and specific lubrication quantities/qualities, like demonstrated in this diagram:
Putting some watches next to my ear as I wind it I can hear this. For example on my 7750 it is always exactly 8 clicks of the ratchet wheel between each time the sound of the end of bridle slipping into the next notch is heard. You can't expect this kind of consistency relying solely on friction with a smooth barrel wall.