Rule number is very important, some delusional people call themselves professional gamblers, all they do is rely on gambling without having a source of income. Trying to make gambling a source of income is a quick way to poverty. Just like you said anyone that wants peace of mind wouldn't make such a stupid mistake, gambling can't be a business or some kind of investment. it's a game of chance and luck.
Indeed. It can't be a way to earn stable income since many gamblers are not fortunate to win. But some of us are not thinking and still risking their money for the hope it is the answer to become rich. Gambling is a game of luck and only few gamblers had a life changing win through it. It's not wrong to try but don't expect too much to the point you'll use your money (that you can't live without) just to try your luck. Thus, before playing, be aware of the risk so you can prepare yourself.