Nowadays, few people use casinos since almost all major providers have identity verification, which already makes this pointless. If you need to steal cryptocurrency, there are plenty of other ways and I don’t think this is a secret to anyone, mixers are still relevant, there are exchanges without verification, etc. Also in large cities there are offices that exchange cryptocurrency for cash, there have been no problems with this for a long time.
Those who want to hide the origin of funds in casino can be caught easily by the casino. Casino can requesting them to do KYC for more especially if casino suspect for their fund flow. If casino know that they want to hide something from them, casino can do many things including closing their account.
Maybe gamblers are aware of that so they will think more to do that thing. But that will not stop people like them to search for the other place to hide the origin of fund. They think they can still hide their fund or what they do in other place but not in casino.
After all, casino will not let people to do suspicious thing in their place. They will watch all of their members to prevents the bad things happen to their business.