This is just a Western cultural perception and baggage. That if you are good at chess, you are smart. If you can solve the Rubik's Cube quickly, you are a genius, etc.
Getting better at chess, the Rubik's Cube, etc. is a skill. The more you practice and the more passionate you are, the better you get at it. This is just like learning to play the piano or learning to swim. There is natural aptitude as well but its not as simple as being super smart and being able to strategize well using intelligence. That's just the narrative that seems to make sense. Being good at chess isn't evidence that someone is smart in general.