I'll address this one.

First of all, I don't think the image source you took as reference bear any justice. The statement was "we require users", not "we require every users".

Regarding the KYC itself, as far as I know, casino... crypto casino are in a constant battle between offering anonymity and govt. compliance. Several platforms explained their situation regarding this "selective" KYC across many threads, that they always strive to keep their customer anonymous, understand that it's something their customer prefer, yet they still have to be compliant to govt. rules. Thus they'll prolong KYC/AML as long as they can; if their customer didn't do anything that require further check, like depositing without wagering [in line with AML compliance] or cheating the system, they'll quite likely won't ask that.

Sadly, sometimes these leniency also backfired, where they later caught multi-acc abuser only when they crosschecked the data, or people bypassing their georestriction. If you didn't do anything that's against their rule, then them not asking you to perform KYC actually come in tone with crypto casino's wish to keep their customer free from privy eyes.

Plus, voluntary KYC are always available, if you want to perform KYC, you don't have to wait for it to be asked, the page are always there, minutes away from being completed.