Most people will ignore what other people say because they haven't had a bad experience with it, but if they have experienced repeated failures even though they have tried many times, that's where they will be based on the fact that the advice given by other people is the right one. For now, just let your friend continue gambling, all you can do is give him endless advice and direction, after all he is your friend.
I think even those who have been gambling for a long time still ignore what other people say about their losses and will continue to gamble as long as they still have the funds to gamble, because every gambler who gambles with emotion and greed of course they will never care about what other people say is that they will continue to bet even though they have experienced several defeats and they only realize that after they can't get the results they want, they then regret what they did.