It seems very self evident to me (given what we now see with legalized gambling) that the harms of broadly legalizing it and creating an industry around it far outweigh any harms associated with black markets by a wide margin. Also, black markets for gambling still exist, so this kind of just feels additively worse. Just from a measure of utility, even if we went back to only having gambling performed with organized criminals breaking legs when people can't pay, that would still result in significantly fewer ruined lives, significantly better quality of life for the communities that are having wealth sucked out of them and into gambling syndicates. It's entirely unproductive destruction of wealth, robbing from the poor and giving to the rich. If gambling made anything better in net for society, gambling syndicates would never attempt to legalize it.
