^^^^this^^^^
So much this.
I started playing Aion as a young teen, I was perhaps 12-13 or so, and it was my first serious game. I have became enthralled by the feeling, the visuals, music, lore and the unobvious lessons it taught, and the game's art style has even influenced my own.
For my legion I used to be a "loremaster", and a storyteller, so I would gather the interested wingbacks in idyllic places every week or so, to present them bits of lore. What the dredgions are, what is the nature of aether, the presence and motivations of Aion himself, the symbolism and dynamics of the Empyrean Lords. Sometimes, I would go for completely nitpicky things, like differences between a Shugo and a Shulack, and my (failed) attempt at reconstructing actual Asmodian and Elyos languages. The legion was a complete noob party, we couldn't organise a single instance properly, we got wiped every time everywhere (except for Sauro on the 5th try, and we only were so stubborn because of the skins), but the sole immersion and friendliness was the amazing thing about it. No rush, anywhere, ever (we once spent 6h straight in TS). We also did plenty of role play. We basically copied the Empyrean/Dragon lords and put them in a variety of absurd situations and drama.
The vastness and ambiguity of presented information in this game is what is so great for me, it reminds me of the original Nier. Just bits and pieces that you need to gather, and put them into a whole yourself. One of the highlights, for me, was being forced to accept that I have been brainwashed as an Asmo, and had to make an Elyos, just to get the other side of the story. Such a seemingly small thing, but it made me realise of stupid it is, to just be told "hate that group", and actually doing it. Quite an important thing for a developing mind, though. Of course, all the movies and media say it, but nothing is quite as powerful as the game playing YOU, and then having to wake up from the propaganda.
Being such a nerd, of course I explored every corner of all maps, and did most of the quests that interested me (although I had a completionist friend who did all the other quests for me). The sheer size of the game guarantees that there is something for everyone, and I still find small unseen details, even after so many years.
Now, I was happy to find this server, and the first thing I checked was NPC dialogues, to see if they had their text intact, and it was basically one of the major factors that kept me here (I got burned on some other private servers, as they deleted everything that wasn't quest dialogue).
I left the official game around 5.6, because I just could not stand the decisions of the devs. 4.8 and 5.0 and onwards were pretty horrible from my perspective, as I cared so much for the lore and artistry, that it pained me to see someone's work thrown to trash. I did love the mysticism of 5.0, the reveal of Tower of Eternity, a lot of the lore and maps, but otherwise it was painful to play. I am glad to come back "home", though, even if I know this is frozen time in the lore, and I cannot expect better patches coming.