Well, teaching someone about gambling depends on the primary goal they have in mind. For example, it happened to me that my friend, a female, met me and asked me to teach her how to gamble so that she could make some money from it, but I declined her request and advised her to look for another side hustle that could produce a more sustainable income. But if she had told me that she wants to learn gambling because she wants an activity she can have fun with, I would teach her.
If you teach your friend about gambling, @Dewi Aries,you can as well guide them not to become addicted.
Sometimes, for example, someone says that he will become a responsible gambler and then asks you to teach him, it doesn't mean it's impossible for him to eventually become an addict, because after all, if we talk about gambling, it doesn't mean it's impossible for a gambler to experience a change in perspective towards gambling, and usually this change in perspective and interest can change when they find something really tempting, such as managing to win a large amount accidentally and obviously this can make them experience an increase in the activity, meaning the goal is to have fun can turn into a goal of making money subconsciously.
On the other hand, yes, I understand what you are saying, that I can guide these people to remain in the right mindset and perspective towards gambling, but I remember one thing here, that in any case it is impossible that I will always be able to supervise them all the time. , I don't want to take risks, therefore I spontaneously prefer to reject them regardless of whether they will gamble responsibly.