Even in your comment you can see the challenge with education and gambling. In practice the return on a dollar (just a different formulation of EV) is often legally mandated to be something around 0.9 and for many games is very close to fair.
But variance, not expectation, is where casinos get their edge. The “Gambler’s ruin”[0] demonstrates that even in a fair game the Casino will win due to their effectively infinite bankroll compared to the player.
You can also simulate this yourself in code: have multiple players with small bankrolls play a game with positive EV but very high variance. You’ll find that the majority of players still lose all their money to the casino.
You can also see this intuitively: Imagine a game with a 1 in a million chance to win 2 million dollars, but each player only has a $10 bankroll. You can easily see that a thousand people could play this game and the house would still come out ahead despite the EV being very much in the players favor.