[Gorthaur the Cruel]

You're forgetting that the Three were not just for preservation, but also enhanced the natural abilities of their bearers. And I doubt that once the Great Rings lost their powers, the "enhancements" they've been gifted for using it would simply disappear. Take Frodo for example. Only a couple of times has he placed the ring on his finger & already acquired some "otherwordly" knowledge such as percieving Galadriel's invisible ring. And even unto the end, Bilbo & Frodo were "tainted" with the One's power & had to sail for West. With the three, perhaps they were "tainted" with the same knowledge as well but of the good side. Surely Galadriel & Elrond would seem a little higher in personal character (for they held their rings for thousands of years & who knows what attributes they've gained & increased), strength, wisdom, & endurance compared to the remaining high kings of Valinor who bask in the protection of the fence of the Valar.