I think that is the explanation of what centralized crypto gambling is. I mean if you just deposit your money into a casino and then you just play there the way you want it doesn't have to be bitcoin that you are playing with, it could be basically a number that represents how much bitcoin you have and win/lose that is it.
It doesn't really change much in the gamblers hand because you end up with more or less bitcoin according to what you win or lose but in the end there are no transactions going around in the background involving your money. Its not like early satoshidice days where you literally have to send money and if you win they sent you back and so forth. That is what decentralized casinos are trying to bring back to remove the central ownership of the casinos.
People are interested in whether there are gambling sites where the game is not based on databases and numbers, but on the basis of the Bitcoin blockchain. However, I do not see the point. If you play games on the blockchain itself, you will need to pay transaction costs, and this is expensive.