Ha, I met my now-wife on WoW so long ago :D.
I guess I consider myself lucky I never really got addicted to that point, as in, I never even maxed a single character. (I had a bunch of them in various race/class/faction/server combos though...later found out I had ADHD lmao)
I mostly treated WoW like a chatroom with a game attached hahaha.
I totally understand the draw though, like, I LOVE MMOs as a concept but I hate how difficult it is to make an ethical one that doesn't waste players' precious time, or incentivize addiction. I feel like there's an answer buried in how some MUDs operate(d), somehow... before casino psychology was introduced.
Reconciling the desire to pop into a "meta-verse" (screw you, facebook, that's our word.) to socialize and cooperate with others, against our finite time constraints on various scales, is a difficult challenge.
I could ramble on and on, but linear level systems definitely exacerbate this. I never played as much as my always-online friends so we'd all start characters and suddenly by next week they're all level 30 and I'm still like 13 and I'm like "K nvm."
But it's a very human thing to enjoy a sense of progression. Hm...
I'm glad you were able to break free though! We're similar in our gaming lives. Instead of one monolithic game, we pass the controller on single player games or play co-op stuff, and get a wide variety of experiences. :)