A person who has been going to physical casinos will never like online casinos. They go there for entertainment and not for only gambling. I understand why your grandmother did not like online slots as it doesn't give her the satisfaction. At that age, it is not that easy to understand how to access an online casino. If you do try to explain to her she would get confused that is why let her do what she wants to. By the way, I have never introduced any senior or elder to online gambling
Wrong, many gamblers who previously bet and played at physical casinos now prefer online casinos and this is because of all the convenience that online casinos provide to all gamblers.
But if he is an elderly person then obviously I sure that he will never like online games like slots on gambling sites because this is new type of game.
And those elderly people who used to play in physical casinos will not have encountered slot games in their youth or while they were in physical casinos, it just that now many casinos provide slot machine game options with various types of games.
In fact, there are many special places that only provide slot games with various types of modern machines which are quite interesting.
In context like this, it is clearly challenge to teach older people to understand online casinos, they may be less likely to trust online casinos because everything works digitally.
I myself would never be able or willing to provide understanding and teach about online gambling to elderly parents.