The essence of cryptocurrency is being secured and anonymity. With the centralized platform, the players do not have any more rights because upon creating an account, they agree with the terms and conditions that there's the information needed for them to proceed to make a gamble, be entertained, and more. Some casinos offer a non-KYC or at least a level 1 KYC etc, which requires an email and phone number for part of the verification for account recoveries. The essence of being anonymous might not as we expect. Some trouble with accounts now requires a higher level of KYC that makes the player more expose with the data privacy.
As you rightly said, level 1 kyc might not be a threat to the anonymity of a gambler
Anyone can use a throw away phone number and email that is not related to their identity to open an account and complete a level one kyc on the casino website. Where the major problem lies is when someone is expected to begin submit their document and scan their faces in order to be able to withdraw their funds in a casino that has initially promised to be a non kyc casino.
The way I see things, if I see anything that asks for documents as a threat to Anonymity, if you give your ID or your cell phone , passport , they will know who you are, and they also know what they do, where you live, that is enough for anything, not just for hackers and criminals , but for keeping track of people who always have casino records and know they have crypto , which makes governments an easy target to pay taxes on, and having different ways of being able to have them in a system where the yoke will always be there, that's what I don't like about a kyc because the governments take advantage of that, you don't know when they will take something from you or ask for something.