Are casinos really interested in money laundering? They earn anyway from regular gamblers. If I was the casino owner, I would not risk my reputation in exchange for % for money laundering. I am not quite sure that casinos are also involved into income legalization schemes today as they used to do in the past. If casinos were really up to money so much, they would cheat users instead.
If they are operating legit, they would take a look for big depositors on their casino especially for licensed ones. But if the player is just using small funds, they won't flag down him for money laundering. Usually, they will notice if the player is depositing big funds, winning high amount or withdrawing big amount of money. But if you are just a small time roller, they won't notice you.
Mixers were purely decentralized and there was no KYC or AMLCs in mixers and you only insert your receiving address amd send the coins to the mixer address and that is all. But in crypto casinos, you have to verify the account with KYC so it is not easy for the money launders to use crypto casinos to launder funds.
Oh yes they were about to use it but when casinos owners discovered it, they started asking for KYC. So it is hard for them now.
Some will try to launder their money thru crypto casinos but if they will start depositing big amount one after another, it will surely create a flag and the casino will investigate more of the account. Hence, they may do this without a problem in the first few tries, but in the succeeding attempts of getting in and out of big money, they may face trouble on the site.