Investing in casino tokens is similar to investing in gaming tokens like AXS, ATLAS, or ILV. They can't be considered a long term investment and is only profitable during their hype. They are also centralized so there is no guarantee that they will survive for many years and if the company owning them shuts down, the token will be abandoned and its price will definitely lose value.
That's pretty much similar but the thing that makes it different is if gaming tokens have more utilities compared with the gambling tokens. Gaming token can be used to buy NFT that will give us daily profit if we are playing the game unlike gambling tokens that can be used to receive dividend only. These tokens are all depend with the hype in the market. As long as there will always be the hype and it will exist. Some gaming tokens have no users at all but they have price. Basically these are speculators who are still buying and holding tokens pretty much the same like gambling tokens which have been using by the people and speculators that's speculated the price of token for the future