In my opinion, aging, and eventually death, is the answer to the problem that newcomers face when coming into a world which is already full of high level, undying characters. I know I am going off-topic here because the original post only concerned visual aging, sorry, but just look at the current situation. We have scores of high level and Mastered characters about and this puts a tremendous pressure on newcomers to grind levels as fast as they can so that they can join in with what everybody else is doing. Which means grinding and that leads to burnout, and also means that they don't go through the same experience that we older players did when the world was young, and which is a part of why we are still here. Look at how many departed players came back when Cho was opened!
Noone wants their character to wither and grow feeble, but there's a lot of good to be said for character aging, and even though it might sound paradoxical, making character life finite, and even short, would improve the longevity of a game:
Aging would recycle the established playerbase, encouraging or even forcing them to make new characters, and that would breathe life into the starter isle (I just read meitemax's post on the "Help Save Cho" thread). New subscribers would feel that their only disadvantages compared to the older players would be their lack of knowledge of the world and their lack of a heritage. (Heritage could be a mechanical accumulated bonus for long-term accounts, or attributes passed from parent to child by lineage, as well as inevitable connections and friendships.)
When character longevity is well balanced against levelling rate then none of the players will shout for higher level caps - that situation is a dead end since the development team would have to be many times larger than the capped playerbase to have even the first hope of keeping the hungry and competitive players happy. So the developers would then be able to focus upon the existing world and storyline, and use ALL of the existing resources to create new areas, not just the level 200+ and non-existent 250+ resources

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I tried to keep my thoughts concise, there's much more I could add on this topic

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/end off-topic