The gambling I know that always ends in the favour of the house hardly benefits the gamblers, but just a few, and it's out of luck, to be precise. Whether you gamble for fun or for profit, it is not certain that one could win out of luck the game they are playing, and this is why gamblers are advised to gamble for fun and not for profit.
Gambling should not be seen as a quick way to make money, otherwise, it would lead to addiction, and this would happen as a result of the chase for repeated losses, which would not go down well with the gambler.