How could you possibly launder money with cryptos?
Let me tell you how, you buy crypto with your dirty money
[1], you can use a mule or smurf to split the bulk amount of crypto that you've bought from your dirty money with and those smurfs will register on a casino and put their crypto in their and depending on your instruction, the smurfs can play a part of that crypto and then they withdraw that money or they can just withdraw it after depositing I'm not sure about this part though but I think that's the reason why casinos are restricting people from withdrawing without playing or withdrawing without a KYC and then they might also use some mixer to further muddle their tracks of the laundering and there you can enjoy your "clean" money. I think I'm wrong with my process but if anyone will correct me, feel free to do so.
[1] You buy the crypto either with P2P online or physically, it depends on where the dirty money is but I believe that most of them do a P2P physically.
This is the main reason why nowadays almost every crypto casino is requiring their players to provide KYC even after complying to the required wagering because if they sense that there is a possible launder , but also this is how other casino abused the system to even asking for more tight security to at least have a chance to the players never comply and yes to remain the funds inside the casino.