I agree with you, OP. Following these guidelines is essential for becoming a smart gambler:
1. Have a side hustle that earns you money weekly or monthly.
2. Only risk what you can afford to lose.
3. Lower your expectations regarding gambling outcomes.
4. Remember that success in gambling is unlikely; the odds are 1% success to 99% failure.
If you truly want peace of mind, don’t rely on gambling as your sole source of income. Consider getting a job or starting a business. Enjoy gambling as a source of entertainment rather than as a way to make money.
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.