The Tiger Saber Gang had "restructured" into what is now the Qingyuan City Management Company, and its ability to generate money had dropped by at least a notch.
In this era, the quickest and most lucrative way to earn money has always been to break the rules.
Opening a casino and earning a cut as the house could make money, but it wasn't nearly as profitable as getting croupiers to cheat, setting up traps to con people, and then profiting from usurious loans.
Opening a brothel, the most lucrative method would of course be to force buying and selling, pressuring the innocent into prostitution, and then making them earn money for you until they die, without even the need to pay them wages.
Besides, the profits from opium dens don't even need to be mentioned; once open, they're guaranteed moneymakers, never worrying about being unable to sell the goods.
But the Qingyuan City Management Company does none of these things.