That also doesn't account for the fact that running competitively is much more popular than playing chess competitively. America currently has 2 of the top 3 highest rated chess players in the world yet I only know one person who plays competitively meanwhile almost every high school has a track team
I think you're out of date. Chess is taking off. I promise you every high school has a chess club and there are many more kids playing chess than training for distance running.
Carlson has the highest rating ever recorded- 2882. But hitting 2900 means he has to continually beat the best players in the world at OTB chess, which he no longer wishes to play.