I can assure you many people gambling on slot machines think they'll come out ahead. Gambling can be extremely addictive and harmful, to the point the addict stops using logical reasoning.
I don't think they actually think they will come out ahead. I think they are willfully ignoring reality. Gambling addicts also lie about how much they have won gambling, but that isn't because they can't count, they just ignore the inconvenient reality, because being aware of that reality would be extremely painful when you don't feel like you can control your addiction to gambling.
Gambling is easier to understand than investments. That being said I agree there should be more regulation. You should be required to state excatly what expected value and variance is when you offer gambling games. Same with fees. "This slot machine pays off 45% of your bet on average and here is how often you win X, Y, Z" or "organizer of this poker game earns about 90% of deposited money in rake and other fees while the remaining 10% is cashed out by the winners".
It would be a better world if we had regulation forcing such disclosure but it doesn't mean that if we still don't have it for gambling we shouldn't have it for things advertised as investments.