Some of them also likes surprises, you'll never know their KYC unless you have a big amount of profits in your account and they will suddenly requires it just for you, like they will require a lot of personal informations for you to pass their KYC but in the end, they still won't let you withdraw it, which is infuriating.
It will be a big issue if suddenly they want to change their terms just so you cannot withdraw your earnings because it is a big amount, this is a big warning sign, and worthy to create an accusation thread in the scam section, that is why you should only play with big online casinos if you are going to deposit a huge amount because the big and highly reputable gambling site will let you withdraw and will not play dirty by immediately changing their rules, always get updated on any changes on their rules so you can change shift in your playing whether you want to continue playing or go for other casinos.