Those who participate in gambling basically know that gambling is a game of chance with uncertain possibilities where if luck favors them, they can earn good income from gambling. Again, gambling often brings such bad luck to some people that they spend all their income and wealth on gambling and yet cannot earn a single penny. But those who participate in gambling despite knowing the uncertain possibilities of gambling basically participate in gambling according to the amount they have the ability to lose.
Only a reckless or addicted gambler will end up losing all their wealth in gambling even when they are not winning. As a responsible gambler, if you are not winning, you will know that you are on a losing streak, which you need to take a brake and continue later after you have recovered the money you have lost so far. So people gamble for fun and that is why they don't permanently stop gambling despite that it's a game of chance.