If a gambler chooses the right game, he can definitely make a profit and most importantly he always learns from experience.
and from what I have explained, does it prove that today you already know people who generate sources of income from gambling?
Right game is not enough, the right startegy is important as well as that will give you the win, a consistent win that we are all wanting for. One shot or big shot win could make us make big money but we will still come back to gamble, and that will eventually result to losing what we won, so it's not working, we need some kind of consistency to gain that profit.
Unfortunately, there is no consistency, or should I say, a guarantee of or for consistency when it comes to gambling winnings, for even when we play games where we don't actually leave all our winning chances to luck alone, we discover that we are still very much at the mercy of luck to win at the end of the day, for example, games like sports betting is one that a gambler doesn't have to totally depend on luck, but we discover that even after the whole knowledge we have in sports, and after the whole research and analyzing and all that, we predict whom we think would win the match, and still to pray that luck be on our side so that the team we have placed our bet on to win the match actually wins.
So, in the nutshell, as long as we still have to too dependent on luck in gambling games, it's close to impossible, or even impossible in practical sense, to have consistent winning in gambling, so, even if one wins a good amount at the very beginning of their gambling, there is still a very high chance that he or she will still lose it all back to the casino as long as he or she keeps playing.