In order to open a casino in real life, you need a lot of money to make it all work properly, and you can't do without advertising
It seems to me that the main problem of opening a casino in the real world is not a large amount of investment, but the fact that it is a very criminal business. No one will be allowed into this business. But on the Internet to become a co-owner of a casino is possible. It is still possible.
For example, in some countries, gambling was banned altogether, because people lose all their money because of it and have new problems, even tritely with their family.