I think many casinos still allow their users to play gambling without doing KYC and I think casinos have restrictions for gamblers before they do KYC.
You don't need to use a lot of money to avoid KYC even though later the casino will ask you to do KYC.
So as long as you don't use big money and don't withdraw too big winnings, I don't think the casino will ask you to do KYC.
We must limit the use of playing gambling in any casino, especially if we don't want to do KYC.
In many countries casino informs tax inspections about big winnings. Nobody wants to pay taxes from his winnings.
Also it is necessary for users to be sure that the personal data of users are kept in a safe plays.