All the people are not the same so there are many variations in their way of thinking. KYC seems normal to some but dangerous to others. Overall casino gambling platform can benefit a gambler in several ways. In particular, it is possible to get proper solutions for withdrawal and account related problems. Now a days a gambler's personal information is stored securely in all the reputable casinos or gambling platforms. A gambler can be involved in various types of crimes. Once KYC is completed, casino gambling platforms have information of the customers so that no one can commit crimes.
I agree that everyone isn't the same and some people won't care what happens to their information but for those that are security cautious when casino make it a must for KYC to be done they're not been fair to this users and besides they can't protect the users information.
All popular casinos are centralized and centralized system don't have a good record for protecting users information. The servers are hackable and our private information can be stolen then sold to those that might use them for crimes and we get indicted without knowing.
Casino benefits gamblers that's why they have to respect the rules of the casino to pass the KYC so they can withdraw theirs wins but it's because they don't have an alternative way out if not gamblers won't have been completing KYC because we know they aren't saved.