This varies between countries as to what the players can turn into profits or not. In the US there are these gaming groups which are paid well because of their performance and they are taking part in every tournament out there, I am sure you have heard of such groups or seen them online.
Did you mean those who play e-sports? Because you are right USA indeed has the most esports players in the world. It is followed by China playing in second and Brazil coming home in third.
Source:
https://www.statista.com/statistics/780631/esports-competition-country-number-of-players-world/I think we can all agree on the fact that turning a passion to a profession also needs the right circumstance, otherwise it just remains a small time hobby.
Whether that passion of yours is recognized in your country or not will matter especially if you are not that rich to begin with and you need to go to other countries to be recognized.