Here is a table that links IQ scores to rarity. An IQ of 190 for example is about one in a billion. We would expect 7 people on the planet to have IQs that high.
https://www.iqcomparisonsite.com/iqtable.aspx
I heard there is a simple formula linking IQ with chess ability. Multiply your IQ by ten and add a thousand. That should be your target maximum ELO rating as a full-time chess professional. Applying that formula to the world's all-time top players, Carlsen would have an IQ of 189. Kasparov 186 and Caruana 185.
That doesn't seem weird to me at all. With a billion people you have the resources to produce top competitors in a range of sports. And it's also not surprising that some people would rather put their time into the most internationally recognised of a set of somewhat similar games. Of the three you mentioned that's chess. (And if you really must attach a demonym to it should probably be 'Indian', there's nothing American about the origins of the game.)