Gambling is unique in different locations, by your assumptions, what do you think people around you gamble on the most in a casino?
Do you think table games like Baccarat, Blackjack, Roulette, Poker, pool? or Gaming machines like slots, random number games, or sports?
When a new casino is about to decide the games to have on their platform do they consider the popular games in the specific regions where they intend to make their gambling services available, or selections are usually based on popularity of games generally?
It is based on both, if a particular game is popular in a region, then it is obvious they need to implement that game or they will lose a lot of customers because of it, but they also need to bring the most popular games or the same will happen, this is why you can find hundreds of different slot machines in a single casino, as they are by a wide margin the most popular gambling game online and offline that exist.