But then why would you choose to go to this fake casino? If you also have the choice to gamble for real and at least a tiny chance to get something back or if you have high hopes "win", there seems to be absolutely no reason to put money in this game or fake bet app. Am I missing something?
What is the reason for playing any computer game? To get a dopamine fix by reaching some virtual goal. People pay small (at least at first) amounts of money for access to the game or in case of free-to-play games for a better chance of getting to the next goal. If someone gets a bit of excitement every time they win a virtual jackpot, they might think a $1 is an acceptable price to pay for it. And then it just spirals out of control.
I think the answer is in the question. They're not playing to win money. They're playing because whatever rewards that have been engineered into the game suck them in. Social aspects, FOMO, "winning" at a game, etc.
Different people crave different rewards. Some people may care more about the financial reward, but they're out playing some other gambling game that caters to them.