Everything we personally do will mostly be forgotten in short order in basically all cases. Even the exceptions do little more than stretch out the timeline by a bit. Jeff Bezos of tomorrow will be the John Astor of today; many, if not most, young developers have never even heard of John Carmack. The only real legacy we can ever truly have is our children, because they will be the humanity of tomorrow.
In 6th grade, I had gone to a chess coach who were a friend of my father (technically my father knew his father very well). It was my birthday/a day close to it IIRC and I wanted to learn chess. He was an international-master (or close to it) /National-master (I think he just had one norm less) and he told me about his story and everything, but he said that in a way, he does feel like if he had put the efforts within something like finance for example, he really could earn more than 10 times the money but he said that he really loved chess with a passion. I think that is another element and I think he was within his 30's. Not everyone makes it even that big within chess aside from a very few at the top
You are sort of right in the manner that, as teens grow and the focus of life/dedication from teenage years on solely getting good at chess, diversifies into for example relationships/money-aspects, the mind simply doesn't have enough competition to play chess Comparing this to a 18 year old or 17 year old who just wants to get best at chess and doesn't really want anything else other than chess with their complete and utter dedication.
(There is also another theory recently within Chess of the pressures of being the world champion, from Ding Liren to Gukesh, both have faced tremendous losses after being the best, Gukesh has even lost 75 points after being the world champion, which I believe also has to be because of how many eyes/the pressure building up)
I still like playing chess but all of this makes me also appreciate all the chess players as well in a bit-more behind the scenes manner too. At professional level, calling it taxing sport mentally might even be a bit of an understatement especially for the people within their 30's.
another thing I personally like about Ding and Gukesh both is that they are both humble. They might win or lose but with the brief time that they both had/will have the crown is with their own humbleness. I really like them both a lot. Hope history remembers both their struggles and their humbleness.
He didn't compete for the world champion becaue he didn't want to put in the effort for the preparation (again). Also it would have been boring if he played it because he would have won again.
He intentionally starts with subobtimal openings at major turnaments because of boredom and still wins.
Regarding boredom, I think that either it was magnus or hikaru who are/were really optimistic about chess960 (randomized chess essentially) because they have less value to openings and more values to the more live-ness of the situation so it has some exciting element to it.
At a certain point for magnus, there really is only enough excitement within classical chess if you are the best players in the world. But he seems excited about chess960
(Edit: you have accidentally made me wonder but would hackernews like a chess club of our community [preferably within lichess]?) https://lichess.org/team/hackernews-chess-club (The password is dang) :]
Edit2: Interestingly, there is already a hackernews-chess-club after searching back on hackernews, https://lichess.org/team/hacker-news, but they had the idea 6 years ago interesting :)
Carlsen's paradoxical because he's undoubtedly the strongest player in contemporary times, if not in the entire history of chess, but his world championship matches have never been particularly impressive. And he thinks that his ability peaked sometime shortly before his match with Nepo. So he probably thinks there's a fairly good chance of him losing if he played another world championship match.
On top of these observations, the one player he was willing to play a world championship match against was Alireza Firouzja. Alireza has an extremely poor record against Magnus, especially in slower time controls, had no experience in the pressures of a world championship match, and Magnus would have been an absurdly huge favorite against him.
In other words, he's not playing a world championship matches because there's a reasonably good chance he spends months of work and effort preparing for it, only to ultimately lose and put that mark on his legacy. Right now it's still perfectly reasonable to call him the GOAT, but if he lost to somebody in a WCC match, that'd now always come with an asterisk.
"My favorite player from the past is probably myself, 3-4 years ago.", Magnus Carlsen, 2018.
Not everyone survives to write to an old age.
Old people have health problems that can prevent them from work, like going blind.
People who write a great work at an old age will not have the time and energy to do all the non-writing parts of making the great work seen by readers - which has always been a big part of writing. Like getting their book in bookstores, advertising it, etc.
If someone is a very talented writer they are likely to write great stuff before they get old and may spend their old age preening and working on their legacy instead of new works. They will already know they're a great writer, so the drive to make another great work is lessened.
If someone is already an accomplished writer more of their time will be taken up with invitations to speak, being on award panels, doing interviews, writing introductions.
There is less financial incentive to write a great work when you're very old.
It is harder to be part of a literary salon full of smart people that help you grow your creativity when you're very old.
As people grow older they become more alienated from the zeitgeist and are better at connecting with their own generation.
But on the other hand, the world is very complicated and you can't know much in your 20s. I'm today a much better programmer than 10 years ago, even with slightly less brains. You are not going to write an impactfull novel without live experience.
How that declines varies and some people still have most cognitive capabilities in their 70s.
I think there's something similar in chess where players tend to peak around their mid to late 30s. But a major issue there is that that's also the age that most players are having children and developing ever more interests. And they're competing against the younger generation which is still dedicating 100% of their life, and time, to chess. Absent some monumental edge, that's a battle you're going to inevitably lose - even if aging factors did not exist.