I suppose this could be what is called an object lession? Sauron did not need such a thing but he also knew that no matter how one might try, one cannot corrupt Elf and Dwarf. In the History of The Lord of the Rings Tolkien wrote that Sauron had made many magical rings for the Elves and there were many elven wraiths but even as such they were not under the dominion of the One. And Dwarves were just to stubbon in their own right to be controlled. But I'm rambling. Evil and greed always wants more. It is not content with what it has and so sooner or later makes some fatal mistake. Casting the One with a portion of his will and power was Sauron's.
It says in the Silmarillion that Sauron sought to gain dominion over the Firstborn because they had the greater power. And the only way he could do that with the Elves is to slowly play into their soft spots (he preached about making Middle-earth as fair as Valinor). Therefore his One Ring and the Rings of Power were a subtle way to try and dominate them, but they were too wise to be deceived.
