So my question now is that can someone use gambling as a means of earning living?
yes, someone can use gambling as a means to earn for a living, but it is not for everyone. you might see people earning for a living through gambling but they are just a very small percentage among all the people who tries to earn for living through gambling. if you are planning on trying to earn through gambling, I suggest yo think it through.
For anyone that could make a living out of gambling is buy a bachelor in the sense that I don't see a family man with responsibilities from all sides that would depend his source of living on gambling, a route of exercise that is unsure and unreliable.