1. KYC requirements reduce money laundering.
2. KYC requirements reduce under age gambling.
3. KYC requirements increase the possibility to hold people to account for their actions. (Exploiting casino systems)
4. KYC requirement reduce scamming
5. KYC requirements can be used to restore accounts after it has been hacked. (Using the documents that were used by the original owner)
6. KYC requirements adhere to government regulations and legitimize a casino.
7. KYC requirements can be used to reduce gambling addiction. (Identifying people that self-excluded or people trying to create new accounts)
8. KYC requirements can be used to enforce regional gambling restrictions.
None of this is actually true. KYC doesn't reduce money laundering, it just makes it possible to attach an identity to a crime. Criminals usually think a few steps ahead and aren't using their own documents for verification. Non-KYC casinos can just ban a player if they are aware of suspicious activity.
None of the other arguments in the list hold much weight either. KYC only reduces privacy for law abiding gamblers and the data collected can be used against them. It makes them susceptible to identity theft, targeted attacks, and unwarranted surveillance.