Feanor's skill

[The Saucepan Man]

If the Elves were the greatest of the Children of Illuvatar, what were men better than Elves at.

Well, the Noldor of the First Age would have laughed at any suggestion that Men were in some way superior to them. Although they befriended the three Houses of the Edain and gave them lands, they clearly regarded themselves as superior. Note that the lands which the Noldor gave to Men were to be ruled by them as feifdoms rather than in their own right. Witness also the (in my view shameful) use by Elves of Hador, his sons, and of course his grandsons, Hurin and Huor, basically as cannon fodder to cover their safe retreats.

Of course, what the Elves failed to grasp was that their physical and mental superiority did not necessarily make them the more important race. Indeed, it is Man who inherits Middle Earth, and it is in this regard that I see Man as being superior to the Elves. Middle Earth ultimately belongs to Man and the Elves were simply there to protect (ha!) and guide them, and then to make way for them.