As for gambling and casinos it's a factor of luck and fun. I agree with the claim that bitcoin has no limits and is flexible, but an asset that depends on us as owners and managers.
Yes, gambling is luck but it depends also on how gamblers are betting and how addicted they are, not because some gamblers are doing well as they gamble not often and they earn but taking into consideration that money that should be used should be the amount they can able to afford.
While gambling, the bitcoin the gambler is using is on a centralized gambling site which can request for KYC at anytime.
It could go both ways but it still depends on some other factors like the gambler and the casino since there are cases where the casino would only trigger KYC when you starting to win too much or break one of their T&C.
Other casinos would allow you to increase limits through KYC and give incentives for doing so. Also, there are gamblers that are willing to do KYC it could become one of the many pros from their view.
Casinos are centralized, they can request for KYC at anytime, it can even be immediately you deposit your coin, you said that already that if the person break the terms and conditions of the gambling site, then the coin is seized. Also if someone has won so big and the gambling site make sure the gambler do KYC, that still arrive at the same point that gambling sites are centralized, even without requiring KYC, they have contolrol over all users account with them.