Gambling is not to be used as a source of income, we should remember that always, yeah OP, only the owners of a casino may it is online or offline are going to be rich, those who gamble will surely lose, that's why when we ask those losers their answers will tend to mean that they only gamble for fun so they never mind their loses.
Even in sportsbetting, it is just for fun but sometimes we get out of hand and we lose our focus and discipline thus resulting to a bigger loss, seldom we see users here bragging that he always wins in sportbetting and sort of making this as an income generating activity.