100% true about chess but I think there's more nuance to it.
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.
Magnus Carlsen is still absolutely destroying anyone else in his 30s. By far.
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.