I would call chess players smart in the abstract sense. Playing chess requires both good "compute power", working memory, and long-term memorization.

But to become grandmaster you have to dedicate a lot of your life to chess. It's not that these people couldn't know general knowledge or do higher math, they are simply not exposed to it. They are not smart in the sense of a universal genius, because that would require immersing yourself in all the things - the opposite of what a chess grandmaster does