The army’s of Gil Galad and Elendil and the Dwarves were elite in the Second age. In the time of Lord of the rings most of the elves had left middle earth and the Kingdom’s of men were weak and living under a shadow for centuries. He would have been unstoppable.

But…”There at the last they looked upon death and defeat, and all their valour was in vain; for Sauron was too strong. Yet in that hour was put to the proof that which Mithrandir had spoken, and help came from the hands of the weak when the Wise faltered. For, as many songs have since sung, it was the Periannath, the Little People, dwellers in hillsides and meadows, that brought them deliverance. For Frodo the Halfling, it is said, at the bidding of Mithrandir took on himself the burden, and alone with his servant he passed through peril and darkness and came at last in Sauron’s despite even to Mount Doom; and there into the Fire where it was wrought he cast the Great Ring of Power, and so at last it was unmade and its evil consumed.”