[Belegorn]

I think the fading usually is with the Elves whereas the age of Men is waxing. I believe the Numenorians were greater than their Edain ancestors. They are said to be closer to the Eldar than to men; "in all things more like to the First-born than any other of the kindreds of Men;" [Sil; 321]. Now their power did wane due to their rebellion and desertion of Eldar-like lifestyle. That's why the Kings in Numenor were only living like 250 years whereas the Faithful still had greater lifespans. Elendil was over 300 when he fought Sauron. Ar-Pharazon felt his end coming when he was about the same age of Aragorn when he died.