~snip~
There is no way for a casino to prevent those underage players. Although, it will be possible if a casino makes the KYC (identity documents verification) requirements mandatory during sign-up.
If that is the case, it can change the crypto casinos if they apply that and make many crypto gamblers not choose the casinos that use KYC during the sign-up. Hopefully, the casino will not apply that in registrations because crypto is about anonymous and we only want to play on the casino that is free from KYC for withdrawing for some amount. Many of us only use gambling as a fun thing.