That is true, casinos show be aware of that they can be used by money launderers as one shop to wash their dirty money. And this is the very reason why government or regulators are very strict as far as crypto base casinos and exchanges because they can be taken advantage of.
And for casinos, before they can get their license, for sure they have been briefed about this kind malicious intent by criminals and that they should be really educate and make aware of it. With that, it will take effort from them and the regulators to catch this criminals who's using the anonymity of crypto as vehicle to clean up their tainted money.
Casinos that comply with regulations certainly have systems and provisions to combat people who use casinos for money laundering purposes. Although there may be loopholes, when there is suspicious activity, especially on new accounts, they will take the necessary action.
Casinos still have to make their policies to anticipate such criminals. Centralized casinos may be better at this. They are more careful not to get involved in crimes that could disrupt their business.