I never knew that someone can use casino to hide the origin of fund. Although if not for a bad intention of a case of stolen fund or hacked fund I don't see any reason why someone would want to go through that process why there are just simply ways to send fund and trade through P2P and cashout your bulks. But any way whatever has disadvantages also have advantage meaning it can be used to keep fund safe from hackers or people who might be tracing someones fund so with this process the destination will be cut short along the way. Thereby bridging the tace.
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.