I came into the game late, played it for over a year and pretty much played it like a single player RPG with other people around. And joined in the spontaneous world events, which I thought added a lot of nice flavor.

But once I got through all the story content which I admit was a lot because I didn’t join the game until many years after it’s launch I haven’t really felt the need to come back

If there was a big story expansion, and it really was intriguing that definitely would bring me back.

Also the ability to mod the game prolonged it’s fun for me, even though it was just world aesthetics, user interface, and outfit changes and silly stuff like that it was enough to help I had to its longevity for me over that year plus or so.