It does indeed thinking about it like that. But since the gears would be bumping into each other rather than just pushing each other would that cause them to deteriorate faster?
Gears are always bumping into each other, one tooth at a time. In practice, the friction of the teeth sliding on each other causes much more wear than the impacts.
In a properly constructed (shaped) gear, the teeth should roll against each other rather than sliding (i.e. the velocities of the contact points are the same).
Sloped / beveled edges, a strong material, and a ratcheting mechanism should keep gear lifetime about the same if I had to guess.
Also lubricated with grease or even bathed in oil which serves as a cushion.