Those involved in money laundering are always looking for new avenues. Nowadays, a very easy way to do this is through gambling sites. But gambling sites are also very careful in this regard. KYC is made mandatory by many gambling sites. Also, if money laundering money is kept on gambling sites, freezing it is also a good initiative, I think that will discourage such criminals from depositing there. They must enter their KYC to withdraw the freezing amount.
You left out one thing: wagering requirements. If a casino wants to avoid money laundering it is very easy with the wagering requirements that we can see in many ToS. That way no one will try to launder money with the casino because it will be too expensive.
But some gambling sites are flexible in this regard for their profit which should never acceptable.
In this you are not right, what money do casinos make without KYC and wagering requirements? Whoever wants to lose track of his money only has to deposit and without wagering anything, withdraw. Deposits go to one address and the withdrawal comes from another address of the casino where the inputs are consolidated and which have no relation to the other. In fact, if the withdrawal is ordered shortly after the deposit, the deposited funds are still in the first direction without moving, thus losing track for an outside observer, and if you do not bet anything, the house does not win anything.
The reasons why a casino may not require KYC or wagering requirements in my opinion are twofold: the first is ideological and the second is to try to attract customers, who do not necessarily want to launder money but who want to gamble in the few remaining casinos without KYC.