Money runs gambling. It gets transferred from a point to another. From the poor to the wealthy, from the wealthy to the poor.
Let's first talk about how the poor gives the money to the wealthy.... They allocate a huge part of their money (which isn't a lot in the first place) to gambling thinking that this would be the quick fix to their problems. This is how they give the money to the wealthy in this case the casino owners.
But the money can also go from the wealthy to the poor. If the tax from casinos gets collected by the government and is used effectively, it can help a lot of those in need. The money can be used to improve infrastructure, education, healthcare and etc.
Gambling is designed to collect money from the poor and give to the rich. The casino owners are the rich people; they deceive the low income earners with very little rewards for winning and make sure that the games in the longrun favours them, that is why they came up with the house edge.
Let's not deceive ourselves further by believing that the poor gain back through taxes. Both the poor and the rich use the roads, schools, healthcare facilities and light provide with monies realised from tax, can we say there is fairness here?