Celebrim
Legend
All true, but "Immersion" feels especially broad to me. And not just with different meanings, but diametrically opposed ones! Especially when used to describe "immersion breaking".
"It breaks my immersion to have to pretend I don't know about trolls and fire."
"It breaks my immersion to have my level 1 character know about trolls and fire." (Or: "It breaks my immersion when other players do that.")
To a certain extent you are right that "immersion" can be seen as just as synonym for "my expectations for the game" and those are of course going to be divergent and contradictory.
For me, "immersion" is that quality of feeling in the game, and I feel it sometimes in both cRPGs and ttRPGs. It's feeling emotionally invested in the story and the characters. It's particularly for me when I'm imagining myself in the situation and acting you my character.
Like, there was a Chill 2e adventure I was playing and I imagined myself going downstairs in the hotel to get breakfast, and because of who my character was he would have read the newspaper at breakfast, and it happened that there was a major clue to the adventure in the newspaper - not something made up at the moment, but waiting to be found. That's immersion. It's that moment where the characters are packing apples in their bags and talking in character as people in the story, and not out of character about the game. It's that moment when the characters are accepting punishment for an act they didn't do, because the player feels his character would do that. It's that moment when the player has a crush on an NPC they way they would crush on a literary character or a movie character.
It's a thing I know when I see it even if I can't easily define it.