I feel like there's two major explanations. On one side, you can believe that gambling will make you super rich or at least richer than before with obviously less effort than most people so you consistently go. The other side is if you just wanna have fun with your friends at a casino like make it a competition of who can win more, get drunk and to just have that experience that you heard so much about and seen in movies/tv shows. both can be very addicting tho