Lol! I thought the very same thing.
Is there such a thing as ‘the golden age of chess’?
That was just TV rubbish.
In a proper chess tournament, you are not allowed to distract, worry or annoy your opponent.
I’ve played in international events all over the world and the only times* my opponents have muttered anything to me would be to offer a draw or a coffee.
*I posted on this board the single exception when an opponent swore quietly at me - the tournament director gave him a final warning.
In the British Championship, I was a piece up in a King + pawn ending (so 100% winning) against a Grandmaster. He played on until the move before checkmate. 
Afterwards he explained he was waiting for another player to finish so they could go for a meal together.
I once saw Grandmaster Nigel Short play on in a lifeless position (a drawn Rook ending.) It wasn’t a rapid game, but his opponent got tired and made a series of weak moves … and lost.
Conceding defeat isn’t common, but neither is it rare in sports. Cricket, sailing and fencing all come to mind. There was also an incident a few years ago where a taekwondo athlete conceded a bout to her injured opponent so the opponent could qualify for the Olympics.
I trust that this was not a zero-sum game, where it disqualified another athlete?
I’ve seen it in a billiards championship game with Efren Reyes. Efren made a crazy two bank shot on a ball close to the rail or something like that and then his opponent conceded a little later without forcing Efren to shoot the final ball in. (It was a dead-on easy shot, but the championship game had been tied and whoever won this one was the winner.) Actually, lemme dig it up on Youtube:
So the situation was this was a race to 13, and both players stood at 12. Shot is at about 3:30 in, and the game is 9-ball. He hits two more shots after the “Z shot” and Earl Strickland concedes without having him shoot in the 9.
I crewed my friends Hobie Cat for a fleet race years ago. It was a two day event with multiple heats each day. The first afternoon for awhile the wind totally died. It was interesting seeing what everyone did to maximize their sails efficiency.
There are only so many slots per nation so it would have to have pushed someone else out. There is probably more to this story like the injured athlete would easily recover in time for the Olympics and was far and away deserving of the spot.
I’m not an expert, but I thought that there were minimum qualifying standards for an athlete to go to the Olympics. If your country has nobody who meets those standards, you cannot send anyone. So “qualifying” might have meant meeting these standards, there might not have been any other athlete qualified. If it were a major sport in a major country, of course this would not be the case. But if it’s the Taekwondo team from a small country, it might be.
As I recall, the injured athlete was older and higher-ranked. I think the athletes were South Korean, but I’m not sure. I’m pretty sure the concession was altruistic and not gamesmanship. I don’t remember enough to internet search the actual match.
In terms of sporting etiquette, I don’t think that chess is unique in having losers surrender when they have a losing position. The form of surrender will of course vary based on the sport.
I played a game the other day where I was up two minor pieces, but my opponent kept all my pieces tangled up. He was actually in a spot to reduce me down to a rook and a bishop and him a rook. He probably could have got a draw after that, but he missed it and ended up losing. And even then he made me get checkmate. Good for him! He doesn’t know me. For all he knows I could have stumbled into a stalemate.
I’ve been in sailing events where the wind was bad and all boats agreed to accept their current positions as the final positions and just return home.
Totally different, but there have also been instances in round-the-world sailing races where boats have stopped their race to assist fellow boats in distress.
Semi-related to the OP, bluffing in sailing is a thing. A boat that’s behind may take a heading that’s questionable if it will have better wind. The boat in front will have to choose whether to maintain their current course, or match the course of the other boat. Similar decisions happen in Formula 1 motor racing.
So to the extent that sports intertwine, running a bluff isn’t necessarily an unsportsmanlike tactic,
Does this happen in cricket? It sounds like it should, but I can’t find an example (not recently anyway).
You might be talking about Pete Goss who in the Vendee Globe, a non-stop, single-handed yacht race around the world, barely made it through hurricane force winds. Then he heard a mayday radio communication from a French sailor.
Goss did a 180 and went back into the storm, eventually saving the other competitor’s life.
ETA: Close To The Wind, the book Goss wrote about the race.
Yeah, it doesn’t happen in cricket at the level of the overall result.
The one somewhat related thing that is true in cricket is that it’s sometimes very difficult for an umpire to judge if a ball has touched your bat or glove before being caught. You are expected to do the honorable thing and “walk” if it you know it has - i.e. to call yourself out.
In most sports, this kind of thing isn’t the norm. It’s not seen as dishonorable to just go with the official’s call even if you know it’s wrong. Football (soccer) is of course notorious for the opposite - for actively trying to trick the referee into making a favorable decision.
That is certainly a possibility that I hadn’t considered.
Thought of a new one.
Would you be upset if your opponent played standing. Not with his head directly over the board to get a complete top down view. Not walking or pacing and certainly not walking behind you. Just standing to get a view that he likes better then sitting?
Yes. I would view it in the same light as the facile psychological trick of the narcissistic CEO who puts low guest chairs in his office so that people are looking up at him.
Yes, having someone do, that would be incredibly annoying.
One thing I have done in tournaments, however, is gotten up to stretch and walk around, and on the way back to my seat, glanced at what the board looks like from my opponent’s perspective. It’s probably my lack of chess imagination, but it’s been occasionally helpful.
If the standing was as you describe, then there’s nothing against the rules about it. So no, I wouldn’t get upset about it. If my opponent genuinely felt more comfortable standing during the game, then I’d be churlish to get upset, and if they did it to annoy me, it would be playing into their hands to get upset.
There are a lot of minor behaviors that are within the rules. If you let them affect your concentration, you’re not going to do very well as a player.
Two chess players are playing a correspondence game. White lives at the South Pole, while Black lives at the North Pole. The postal service is slow, and play proceeds at the rate of one move per year.
After 15 years of play, White makes a daring queen sacrifice, the consequences of which are by no means clear.
A year later, as he sees the postman returning, he is very excited. He feels his heart start racing, as many questions cross his mind: “Will Black take my queen? Is the sacrifice sound?”
He opens up the envelope with the reply and reads:
“J’adoube.”