I totally disagree that it is easy to built or run a casino. Not everyone can own or develop a casino. You need to know How Much Does it Cost to Open a Casino? [Land-Based & Online].
This is not like getting a website, applying a theme and you are ready to start a business. In this business model, you need to have a big initial capital so that you can pay off the gambler's winnings initially from your pocket. Also, the cost and scenario is different for the physical and online casinos and a proper case study needs to be analyzed before you think of starting this business.