Most of the casino projects are not listed on a popular exchanges which I don't know why. Many of the exchanges they are listed are not that known and this alone do many users to be afriad of losing there funds and coins to exchange that has no reputation. How I wish some of these casinos coins are listed on popular exchanges, that will attract more investors to keep buying.
I've been in conversation with one of mod from a gambling token and he said that he will be only listed their token in the exchange site that compliant with them. I can speculate if they were only listing their tokens on exchange site that's compliant with regulation where they have been operated. At least there was a token that has been accepted to be traded in so many major exchange sites
https://coinmarketcap.com/currencies/funtoken/markets/FUN token is listed on binance. That proves if gambling token has a chance to be listed on the major exchange site as long as it has been fulfilling all of requirements by the exchange sites itself.
The hardest thing is to be compliant with regulation and exchange site who wanna listed your token. These are problems why you were rarely seeing gambling tokens gone to the big exchange site.