Well usually it's always smooth until it isn't. They need to keep appearance of smoothly running casino if they want to rug enough money. If problems start at the beginning they get only pennies for it compared to pro hustle
This is called the long con or the big con, while many scammers try to get whatever they can as soon as they can, there are other scammers which concentrate on extracting as much money from their victims as possible, so it would not be rare for a scammer to set a casino and make it seem legitimate by offering a great service and eventually gaining a good reputation, until eventually and without anyone expecting it the casino turns into a scam and all the funds of their customers are lost.