Well, for your information, stake is not the only casino that does not necessarily ask users for kyc verification before the user is allowed to deposit and play, majorly every online casino on this forum only ask kyc from user when the user is withdrawing an amount of money that is over the limit to an amount they accept for non kyced users.
I think you have not heard the update, afaik KYC is now mandatory for new accounts. They started to implement it since last year if I remember it correctly. I've heard this information from new players especially new players who are from the same country as me. For old users, it is still not mandatory as old users are offered to do KYC for extra bonuses. For now, whenever there is a question related to KYC then we have 2 different answers. 1st is that it is not mandatory for old players and 2nd is that it is mandatory for new players. However, it is correct that casino reserve the right to ask KYC especially if it is clearly mentioned in their ToS.