Hmmm, I think the lore/setting needs a certain minimum amount of interesting elements to be compelling, but after that threshold is reached I'm personally there for the characters and the story that is told through those characters. As long as the world feels interesting and provides sufficient incentive to suspend disbelief then it really falls on the characters making thought provoking decisions and doing interesting things to move a story along. I don't really participate in famdoms so much, usually just focusing on the fiction itself.

Imho the best stories get you to love the characters and want to see them succeed, and then place obstacles and opposing forces in front of them to provide a conflict that drives to the narrative's conclusion in an interesting way. The best twists are the ones that aren't too obvious but you can see coming if you're actively taking in the clues, the best antagonists have thought processes that make sense and are self-consistent even if the viewer doesn't necessarily agree with them, and the best protagonists see parts of themselves be challenged and have to reconcile those dissonant elements within themselves to reach their goals.

I also feel that on top of everything else, the presentation in a given medium is also incredibly important. Whether that's a book being well written and coherent or an anime being well animated and choreographed with emotionally appropriate music accompaniment. These things go the final mile in really crystalizing the tone being put forth by the story/setting/characters and making sure it all hits home in the way the creatives behind them intended. The best media for me has both great stories and great presentation that takes full advantage of the medium being used.

I don't consume much fiction, just a couple of TV shows, adult cartoon sitcoms. In those cases I'm more interested in the characters and funny events. Well, I do also watch movies now and then, which are almost all fiction, including some anime movies, mostly Studio Ghibli ones. For movies I guess it's mostly the story and the characters, and in some cases the action. In movies set in the future or past, the setting is also interesting, maybe even the most interesting thing. If you can count the general mystical qualities of Studio Ghibli films (and maybe other anime?) as lore, then I like the lore too in those cases, a lot.

I've only ever participated in one fandom (or actually just witnessed, never really saying anything), Arianators on Twitter. And it wasn't even because I like Ariana Grande (though I did kind of adore her character on Victorious), for much of the time I was following 1500 of her fans I wasn't even following Ariana Grande. I just needed/wanted some source of uplifting positivity in my life, and I noticed that the Arianators were more generally more positive than any other fandom on Twitter.