More than 50% of the world population gamble in one sport or the other and some are making good money while some are still hoping and praying for their luck to shine.
You don't give your opinion as fact without nothing to back it up as 50% of the world population gambling is a ridiculous claim.
Gambling is not a source of income. It surely doesn't guarantee a steady and punctual payment and can't be classified as a source of income. It's that simple. Sadly, lots of people take gambling as a means to make lots of money and get rich.
Do not consider gambling to be a source of income cause it's simply not. Be guided so you don't fall down the rabbit hole in search of riches.