I agre, it's a nice feature but actually doesn't help to addicted gambler.
It's all in the head and strong will, in fact that someone is willing to admit a problem and not trying to foul yourself. That maybe might help to more selfi disciplined gamblers.
You wont really be needing any feature or whatever exclusions that a site must have, just like you have said that everything would really be basing or depending on the control you do have or self discipline
because if you do fail on doing so, no matter how many exclusions or features available there's no way that you could really be able to make yourself that completely stop on doing gambling. You would really be having that kind of problem on the time that you cant really be able to control yourself. Exclusions could neither be available or would really be that something that you could really be able to request on.
This is why if you do find yourself that being impulsive then it would really be better that you should really be that careful or totally completely stopping gambling for a while.
Dont make yourself that playing on constant manner. You cant really that make yourself be able to stop not until that you do bust it all.
True, it won't really be able to fully help gamblers to avoid the possibility of addiction or unsolicited actions because as you said above it all comes back to the gambler themselves which means that if for example they are one of those gamblers who are obsessed with gambling or those who gamble in the wrong way then they still won't take advantage of the exclusion feature because they will consider that the feature is not in accordance with their wishes which they only want to continue using their time to gamble.
I think the scenario may be similar to addicted gamblers where they are immune to suggestions and criticism, they will not listen to them and will continue to ignore something that does not suit them, so even though for example the purpose of the feature is to minimize gamblers from entering the addiction phase, but still in the end all decisions are in their hands which will make them free in terms of making a choice even though the choice will only lead them to a bad situation. So actually the key to not ending up addicted is always in themselves, in the sense that if for example they can maintain their gambling involvement properly such as always prioritizing limits and self-control then without such features they will definitely do many things to prevent themselves from falling into addiction.