For some Countries
gambling is Banned Like Japan where your Slot machines have been replaced with Bagatelle Machines, and they buy a bucket of Balls to play them and can only win Balls Which have no cash value, also there are other machines that pay out Tickets which can only be used for Prizes. so your only incentive is to win Toys etc.
But Gambling is still available to those who want to risk money, and it is rum by the Japanese Mafia. So is very Illegal and can be Dangerous. Much Like When the USA introduced a Ban on Drinking Alcohol, You were allowed to Brew your own Wine and Beer at home for personal consumption but They did prosecute people if they did it on an Industrial scale to supply other people. So the Criminals took over the supply of Spirits during the Prohibition and it became very profitable for them to sell Bathtub Gin etc but where you have profit you had Greed! And a lot of Violence.
Amsterdam Had a similar problem with Drugs and Prostitution and the Red Light district in Amsterdam was a very dangerous place to visit before they Legalised Weed and Prostitutes. Now it is a Popular Tourist attraction,
Banning something does not stop it all together, and only sends it underground, to be run by the Criminals and thugs that would increase Violence between Rival gangs etc, So it is better to monitor it, Take away the Criminal element and Then you can control it! Making it safe for everyone.
If Poker is banned in your own Country, Do you think that it will disappear completely, I very much doubt it, as the Criminals will always find a way to give players what they want, at a Price, Poker was and still is Banned in many States in the USA but there are ways and means of getting your poker "Fix" in dingey Backrooms and Cellars if you cannot get to places like Vegas and Atlanta etc.
So banning something is not going to stop it, You just Criminalise it and send it out of sight! But it will always be there!