Maybe that's the annoying thing for gamblers where at the beginning the casino doesn't ask for KYC but then they ask for it when players win big wins or make big deposits and bets at the casino, that's why I always remind beginners or anyone to be on the safe side, it's best to complete KYC. At the start of registration, if you really want to play with money and big bets, unless it's just money and small bets, it won't be a problem.
I think that's what causes people to not like this KYC because it is too abrupt in asking users to complete KYC at the end of the game instead of at the beginning of the game, of course that is definitely not liked by many gamblers because maybe they don't want their identity to be known just because of a small bet.

Almost of gambler dislike with KYC and many of them not read with term of service required KYC or not, right now have casino platform must filled personal document information help us later if required KYC will use the same data with document ID. To make clearly about casino allowed KYC or not ask the help center and there are fast respond with their costumer service and ask required KYC or not before huge amount deposit or withdrawing.
If some gambler not agree with KYC required still available looking for other casino platform without required KYC before making deposit on casino side need KYC. Don't make on playing victim position when some casino restrict an account without get KYC if want withdrawing huge amount because all casino have provide with read term of service firstly.