gambling is a little bit different, as you have to pay and receive money (easily enforceable bans). But here we are talking about a free service which is also offered by many foreign alternatives (which of course are not going to cooperate.)

The age verification is on creating the account prior to any deposits.

As for not cooperating - I'd expect to ban them altogether (ISP) unless they comply. Gambling is exactly the same.

Those who will trade privacy for safety deserve neither.