You’re right but this days criminal money use mixer instead of casino because casino already have a wagering requirements before they can withdraw and they might lose most of there money if they gamble it since they have huge money that needs to wager unlike on mixer that typically charge small percentage of the initial amount just to make the crypto untraceable from chain analysis investigation.
Most of the user that wants complete anonymous on casino nowadays are just for tax purposes because they can dodge tax report of winnings on crypto casino if it’s not registered under there name.
No one wants to pay taxes, but the state treasury needs money. Therefore, non-payment of taxes is also a crime. Therefore, the authorities and regulators make sure that there is no anonymity and large winnings are reported.