I can't think of anything more profitable at the moment. Although I don't know in depth the income from online casinos.
However, to create an online casino, you need a lot of investment and be willing to pay for advertising and interact in a forum like this.
I don't intend to have an online casino, I'm more interested in having an e-commerce.
One of the factors that makes me believe this is that there is already a whole audience ready to play in casinos, as they are generally people who bet out of addiction, to make money (or even when they lose, they play just to pass the time). In addition to the fact that there are costs for servers, employees, online attendants, programmers and other costs, unlike physical casinos where the costs are for installations, maintenance, energy and employees and security guards...
Do they make more profit than digital banks, CEX exchanges, etc.?
Maybe compared to the bank, yes, the casino is more profitable because there are more gamblers and large deposits. The income is also high, especially if the players in the casino are rich. But compared to the CEX platform, I don't think the gambling casino online is more profitable.
Because there are more people who invest in cryptocurrencies or bitcoins compared to gambling, it's just another thing that people think gambling is good; there are more opportunities in exchange compared to gambling. That's the truth.
We can't deny that online casino is one of profitable business on the internet. Creating one new online casino can attract many people to try that casino but if that new online casino wants to grow their business, they must promotes their casino in many websites. The competition on the gambling business is tight and not all online casino have the opportunity to grows their business so that's why we only know some online casino that can still exist for a long time. The thing that can makes online casino exist and grow the business is because the owner can promotes their online casino and have many members that still comes back to their casino. But to knows for more details, we can't gets the right data because that is the online casino secrets.