Wind speed is hundreds of km/h. So, "turbulent mixing processes" rule. There is plenty of un-oxidized material on the ground. Oxygen just needs to be kept off

Wind speed is hundreds of km/h. So, "turbulent mixing processes" rule. There is plenty of un-oxidized material on the ground. Oxygen just needs to be kept off the carbon. And, it needs stirring. Big meteors could do a bit of that. Earth gets its stirring from tectonics, which Venus lacks.