Okay, let's get something clarified here, because I think Rook is wording things in a way that is causing a lot of confusion.
Rook is talking about "conceding" in a 3-player game by realizing that 1st place is unattainable and therefore playing for 2nd place to ensure not finishing in third place, thereby avoiding the much bigger Elo loss that comes with 3rd place compared to 2nd place.
I would not have used the word "concede" in that context because it has obviously caused confusion with the actual act of "conceding" by clicking the "concede this game" button which saves no Elo and which is not even possible in a 3-player game.
I hope that clarifies this entire misunderstanding
My two cents: I HATE the idea of ever giving up, and I HATE even more the idea of playing attack cards against 2nd place rather than first place. But, given the Elo system which does heavily punish 3rd place in a 3-player game, while minimally punishing the person who finishes in 2nd place, it's difficult to really argue against what Rook is saying. I don't like it, but it's the system in place. The same thing happens in Hearts, where 4th place is an Elo catastrophe, and remaining anywhere close to 300 Elo requires avoiding finishing 4th out of 4, and where finishing 2nd actually gains you Elo. Especially since, in Hearts, there are situations where it is literally impossible to catch up to first place, and therefore it does become a battle to avoid finishing last.
I would much prefer a system that awards Elo to the winner and gives equal Elo loss to all the non-winners. But that is not going to happen, so, the system is what it is.
Elo is not meaningless. It means something to a lot of players (myself included) who find personal value in climbing the leaderboard, especially if they believe they have a possibility of seeing their name in the top (whatever, top 20, top 10, top 1). Anyone can choose to not care about their own Elo, or to say it is meaningless, and that's a perfectly valid opinion, but it's also perfectly valid for any one person to care about his or her Elo. Each person has every right to care or not care about his or her own personal Elo for whatever reason. It IS a scoreboard, to some extent, and so I choose to care about it, just as I care about the final score in any individual game of Terraforming Mars or any other game that l keeps score.
I am in third place in ELo in a game that I like very much. Do I want to be number 1? Yes. Do I believe I can be the best? Yes. (Especially since the top 2 will not play me). Therefore, I care about my Elo in that game. And in a 3-player game, if first place were utterly unattainable, I would try to ensure I do not finish 3rd. For that reason, I ONLY play that game 2-player. In fact, I avoid playing ANY game 3-player, unless it has to be played 3-player (7-wonders, for example), or, if 2-player just makes for a lousy game (Scythe, for example).