Now in all liceneced casino KYC necessary. I passed KYC in Coinplay.com after I oppened accont. It taked several days (2 days) to pass KYC for me. I withdraw money without problem in Coinplay.com. But I never had a big winning sums in casino.
Not all casino. This is just a perception of new casino in the crypto industry. Typically new casino that has license are the only one who ask random KYC to all there players once they request a withdrawal. They are using there ToS under the AML section that they can ask KYC anytime that they want.
Or also by providing betting limits as other casinos do regarding large withdrawals with bets that have reached the limit to immediately do KYC for safe withdrawals and avoid account freezes. Also, the bet limit option is quite effective in my opinion compared to imposing KYC right away, or asking for KYC randomly, which is clearly very unethical as a licensed casino.
Therein lies the advantage of casinos in that they give freedom to their users to always play comfortably without worrying about having to do KYC, let alone requiring several days of approval.