...What makes casinos necessary to be regulated?
What I wanted to say has been said already, which are fraud like money laundering, scams, hack and many others fraudulent activities. Normally casino needs to be regulated to control it's financial security system aspect to avoid money laundering,scam and hacks. Without this regulation, a lot of Casino app would have been compromised. So there is surely need for that regulation for proper security management and the safety of customers.
Aside from that, for the legality of the operation, the government will perform its duty as well to regulate and take control of it. The community gains safety while the government also gains revenue.
Regulation means something good for everyone and perhaps the right thing to do. Because imagine a casino without following the rules, they will surely do what they want. They can attack each other, ruin their reputation, etc. But with the help of strict regulation, we have a fair and safe gambling experience.