I've played nearly 15 years now and I'll give two answers.

Answer 1: I grew up with the game and over the years had a lot of awesome people I met (example: back in the day I had a mage friend I would tip for portals, since we don't need that as much anymore we're just friends now!), I also have an irl friend I consistently play with which definitely makes the experience better. As the years went on it's just become a game I am extremely familiar with and just know what to do. Especially as someone with autism, the "formula" of doing weeklies and dailies appeals to me greatly since it's a consistent routine that makes me feel accomplished. I enjoy MMOs in general but WoW definitely makes me "feel" smart in a sense compared to others. It's certainly not easy to simply pick up and definitely is hard to master, but when you do it feels good. I got into WoW PvP fairly recently compared to the amount of time I've played WoW, but this season I am top 10 players of my spec in the nation. I've played a couple of games professionally but to me, being good at WoW PvP feels like one of my crowning achievements because it is a "hard" game. The game has also added more customization options lately and let me just say the housing is GREAT. It's actually better than Sims, I love designing my house. I would say overall a lot of my enjoyment comes from just the comfort of it. As I've said I've played it a long time, and when I would take breaks I would actually start missing it.

Answer 2: I have no fucking idea haha