I see people commenting that it exists where gambling is prohibited but it exists almost everywhere only because the gamblers don't want to pay taxes and there's high rollers involved here too if they want to launder their money made from other sources or simply it offers more exclusive games that we can never witness in common life. Might be I am influenced after watching Squid games but it's real, in some middle eastern cities where these things are prohibited but made available due to the demand.
Correct, underground gambling is run mostly by syndicates that use this operation to gain profit without paying taxes and at the same time deal with other illegal goods.
There’s a recent issue in my country about this underground gambling called POGO, they have license in the surface operation but they have other illegal services such as human trafficking, drugs and many more that happening behind.
It is what it is, and to be honest even government officials aware of those activities but they will be paid to keep their mouth shut on regular basis, once in a while there will be some news about looking for them but it is not really possible to stop them as long as we have the corrupt judicial system where we can buy the judgement in favour of us with legal loopholes and even if there's no way there will be a pawn to go down instead of the real one, we see those in movies but that is happening in reality too.