I remember reading G.H. Hardy's A Mathematician's Apology that mathematics is young man's game. Can same be said for chess? Is chess a young man's game?
Yes. Though people are consistently impressed by how Vishy Anand keeping up his level, he's 52 now I believe. He was also "late" to reach the world top compared with many of the newer chess stars like Carlsen or Alireza.
World top 10 is a young man's game I believe but you can never discount a former Super-GM, they are still super strong.