I also heard those failed project before so I don't think smart contract is good for the gambling site and mostly of the new gambling site today didn't have their own token because they know gamblers don't want to use any token to gamble, we still prefer the major options and that's the thinking of many gambling site today. Well, if there's a better usage of smart contract in gambling, then someone will develop that soon and maybe introduce it to us again.
New projects that will have that enthusiasm to take over or at least get a chance to maintain their project with loyal customers are rare.
No one stops them from making one but they just have to learn in the past.