Running a casino is a lucrative business which is why we have a lot of new casinos coming and old casinos keep launching new promotions to entice their players to stay, the only way a casino will go bankrupt is through mismanagement and there is a lack of players playing.
The house edge will keep the casinos running for every winner there are 5 or more players losing their money, it's better for a player to play on a stable casino because their goal is to keep their casino running for a long time, that is why they have marketing campaigns in many platforms.