I'm pretty sure that there has been quite a few decentralized crypto casinos already, including prediction markets.
Augur is probably the best example of this.
While this is certainly a noble cause, what matters is if they can actually attract revenue to the blockchain. I doubt this will happen just because of the fact that people prefer the convenience of centralized alternatives right now.
Weren't the casinos like Satoshidice and a few others in past were decentralized?
Surely they were regulated by any government aside from their server which was located in Europe if I'm not wrong.
And what about those sites that used to allow users to place bets on blockchain block's ending letter.