People don't want to be best at something for the sake of it, but because it brings some perks with it - recognition, fame, money. Being the best in a game which literally nobody else knows is largely meaningless. I mean, try it, it doesn't take much time to make up a trivial game. Does it bring any kind of satisfaction to know you're the best in the world (because nobody else knows it)?

(to be fair, there is also inner satisfaction coming from deep understanding and mastering of some activity, but alone it's rarely enough without any external validation to motivate people)