In my opinion, KYC requirements in regulated gambling sites can be viewed from a security perspective. When we gamble on a site that is regulated, it often means the operators need to adhere to certain security and transparency standards. These standards include verifying the identities of their users to prevent fraudulent activities.
As for me, the main problem with the KYC requirements both at gambling sites and centralized exchanges is that it is not known how exactly and for what purpose the personal data of users are used. I mean that if you give your personal data to any company, you shouldn't be surprised that your data can be stolen and used by malicious people at any time. Unfortunately, there have been many such cases in the crypto industry.