Sorry, but I disagree with the legend. Aluminum chainrings will wear faster than stainless steel. This is just the way it is. In addition, harder components all around will exhibit less friction and will last longer. This is why ball bearings/races are super hardened and rifle barrels get chrome plated. Aluminum chainrings are sometimes anodized (like shimano does) and this does create a hard surface, but it is thin coating and eventually it wears through. Once you see shinny aluminum in the valleys of the chain teeth, serious wear begins.
Originally Posted by
conspiratemus1
Mike Barry (Canada's "Mr. Bicycle" and father of TdF racer Michael Barry) says steel chainrings wore faster in his experience racing in the 1950s-60s than aluminum ones. He doesn't know why this should be but says on his blog that he suspects the aluminum makes an early accommodation to the precise shaping of the chain rollers and then stops wearing. Steel always puts up a fight and therefore keeps wearing away. Voice of experience, fwiw.
Replacing worn chains is certainly important. If the pitch of the chain elongates it's going to present an ever-changing wearing force against the teeth of the rings.