No benefits at all for the user to submit his kyc. You dont know what will happen once you submitted it. what if the casino operator gos rogue and sell all the information or get hacked. That is besides the why question.
Yes, I agree with you. Many gamblers will try to avoid gambling site which needed KYC. I think it's not just for the gambling website, but it's for the website who ask for KYC in the registration, and we need to be careful to send the document.
I am too worry if the information that I sent to them will be used for the other things that I don't know. The hacker will easy to get the information from the dark market, and they can use the information for their purposes to reach the goals.