I know about these reasons and i don`t believe that casino will KYC all the gamblers at the start. But now imagine the situation: you want to withdraw money and you need it fast. And at this moment the casino decide to KYC you. And you have to search some documents, wait until the casino check it, etc.
As for me it would be better to KYC during the registration. At least part of it - you can send documents and start gambling while the security check it.
This really creates a very surprising situation for a gambler at that time. Asking KYC at the time of registration would be good for gamblers, but many casinos do not ask KYC at the time of registration to attract gamblers to their site, it is also a marketing policy. But when a gambler wins and goes to withdraw he is forced to KYC which is a tough time for that gambler.
And many times dishonest casinos use this kyc as an excuse to withhold funds from gamblers as we can see from various gamblers complaints. Gamblers should check the ratings and reviews of a non KYC casino before joining to avoid the hassle of KYC in the future.
I think it's good we first establish the facts before entirely blaming casinos for wrongdoings. There are some core no-KYC casinos, and if they are the ones who later asked for the KYC, then they are not sincere and are entirely bad without a recuse. But if it's not a no-KYC, they must obey the AML act because it's very possible that they are fully registered and regulated. Even financial institutions might allow their clients/customers to start depositing and withdrawing money with certain limits or times, and later, they would ask for the KYC to keep the account fully functional.
The normal casino is not different in this regard, only that people are not reasonable with them. It's very good to know the casino you are dealing with, and even if you can't read their terms and conditions to get familiarized with them, you can ask direct questions from their representatives. In this present age, I don't think that any casino that is not a no-KYC would allow your account to fully function without KYC, which is why it's good to do the needful instead of complaining.
I make sure I first do my KYC with casinos, brokers and exchanges even before depositing, this is wise to avoid future issues like that of withdrawal.
Agree with you, if a gambler is interested in gambling in a particular casino and it is a reputable enough casino then it is a good step to complete KYC before depositing in that casino. It is also true that casinos also have to go through a lot of accountability, with serious issues like AML.
However, there are some casinos who promote themselves as Non KYC casinos, but when a gambler makes a large withdrawal request, those casinos create various issues. And those casinos are risky for gamblers. Because I constantly see many complaints in this forum where gamblers ask them for KYC verification while trying to withdraw, crypto users are less interested in sharing personal information so they try to avoid this KYC verification. But in most cases they cannot avoid it.