Casinos existed without the need for KYC's until the government made it a requirement, and they started demanding it. IMO If the government no longer requires casinos to do KYC verification for new gamblers, casinos will go ahead and still do KYC verifications because they have seen the benefits of knowing their customers better than when they just allowed people to come onto their platform and gamble without their knowledge of who they were. What do you think? Do you think some casino's will revert back to non-KYC and allow money launderers, plus other fraudulent people have their easy way with them as a way to attract customers, or since they recognize the personal benefits of KYC to their casino, will continue demanding it even if it affects their customers?
There wasn't KYC verification necessary before because Bitcoin wasn't considered as a currency by governments. Now they consider Bitcoin as money and a currency, so it's equal to fiat in those terms. There are still some casinos with only in-house games that keep no-kyc policy but their numbers are limited. You have to consider that crypto casinos evolved and besides in-house games, they added live casinos, slots and etc... So they are forced to ask their customers for KYC documents in order to offer you live blackjack, roulette and other games because these b2b casino suppliers are regulated and casino needs to meet their regulatory demands too.
It's impossible for casinos to revert back to non-KYC with their current states. If they do that, they'll be labelled as criminals I guess. The only possibility to deposit and withdraw high amount of money via crypto casino without going through human interaction is to use web3 crypto casinos like Metawin.com