We agree that someone presents besides the addicted person to gambling is important. That helps the addicted person to realize that he doesn't fight alone to solve his gambling addiction. He will see that together, he can cure the addiction and become a new person who can overcome the gambling addiction. Maybe it is not easy but with someone or more people besides him, he will realize that his people still care about him and support him to cure his matter. It really means something to him, seeing that some people closest to him want to fight beside him and still stay with him. He will feel that he has the strength to fight his gambling addiction and does not want to be addicted to gambling anymore.
Yes, at least when someone is standing beside them, that person can remind them when to stop. This is certainly helpful, as external factors can also influence a person.
However, the person must also be able to accept this, because if they don't, they may become angry when someone reminds them about their gambling. This should also be done by someone close to them or someone they ask to accompany them to ensure they feel comfortable.