Do not forget that KYC is a way to prevent fraud. No person who has passed KYC will cheat. Another thing is that the casino must provide such conditions that it is impossible to purchase other people's accounts with KYC or pass fake KYC. If casino conducts KYC, then everything should be as honest as possible.
If a person wants to commit fraud and knows in advance that he will commit it, then he will find ways to avoid KYC, if he does not find such ways, then he will go to another casino where KYC is not so hard or there is no KYC at all.