I mean the jerky nature of pedalling on a mtb or cyclocross bike. The disciplines often require a change in cadence, sometimes with half a revolution of big force to get you over that big root or to grind your lowest gear out when reaching the top of a big hill surge in cyclocross. At these points, where you’re pedalstroke is top dead centre and all you need is to just stamp that pedal down, I don’t find the bigger/taller/long part of the oval to be useful and can cause you to stall.
By bigger, im referring to the shape of an oval. An oval chainring essentially gives you a bigger or smaller gear depending on where in the revolution you are.
I don’t disagree that traction can be improved on consistent terrain such as a flat muddy cyclocross corner, a consistent smooth mtb climb and maybe even pedalling through a corner on a crit course