I mean it's better than letting make a deposit, win, and then they block your account and start asking for KYC verification first before withdrawing. We have to be honest, the old days of using a casino the whole entire time without KYC verification are diminishing real quick.
I think you remember what happened to exchanges. Right now you can hardly get a centralized crypto exchange that lets you deposit, spot trade, trade futures, withdraw without any KYC verification.
There are still a couple of sites out there that don't require verification on registration and don't ask any form of KYC later on unless they detect something unusual or if the amount involved is big.
I do agree that zero KYC gambling sites are hard to spot these days, but that doesn't automatically make KYC on registration better for some people like me. I actually prefer the blocking scenario.
As they need to get their gambling license, they need to comply with what is required to their players. And one is the submission of KYC docs. I believe, most reputable casinos and bookies these days are already requiring credentials from their respective players owed to their gambling license.
Most casinos need to apply for license, otherwise, most jurisdictions won't allow them to operate their business. I guess, that's the new norm already in any business.