Indeed, KYC is a requirement that is applied by casino sites for each user, especially for users who will make withdrawal transactions with relatively large amounts.
However, as gamblers, we shouldn't need to feel disturbed and be concerned about the obligation of every user to do KYC.
Because the existence of KYC requested by the casino site has a good purpose in terms of security from the casino site and security for every account registered on the site.
Now personal data very often is hacked but much more often users give their personal data but themselves. In licenced casinos users more protected but a lot depends on the reputation of casino and how long it works on the market. Now there is a big competition among casinos and only the best casinos will be able to survive and work for a long time.