I think people overanalyze MMOs way too much.
I had my best time in WoW during its shittiest expansions because the people I played with were awesome.
I stopped playing WoW because life stuff preventing me from dumping time into an MMO.
I also stopped playing XIV because life stuff prevented me from dumping time into an MMO.
For a genre that consumes so much and is so dependant on other people, I think people overestimate the impact of "the game" on its success. Maybe it matters when a game is new and actually needs to sell itself to potential new players, but established games? They live and die basically on inertia.