If you don't use big money to deposit and gamble or withdraw a big amount of winning money, you won't be asked to do KYC. But casinos can ask you whenever they want because that is their place of business. So I advise you to play gambling only as needed and don't need to use big money, but you also have to be prepared if, one day, the casino asks you for KYC. But you can play at any casino you want, especially if it is a reputable casino. I used to play on Stake and had no problems until now.
I don't think all gamblers will use or deposit a large enough amount so they don't have to worry about KYC requirements.
If we want to withdraw a large amount, there is a way to avoid a KYC, namely by withdrawing gradually with a smaller amount, but we make several withdrawals until all the money we want can be withdrawn.
Maybe for now we can use some casinos that don't require KYC but maybe in the future more and more casinos will impose KYC requirements and we should be able to accept them.