that's correct, gambling as a source of income is not an easy thing to do, in fact it is hard to an extreme, way more stressfull than having a job or doing other things
when you understand how it works it's clear that it's not a scam
most of the things can be understood with math
the main thing is that most lack the emotional control to be able to be realiably profitable from gambling
I doubt that learning how to control ones emotions can actually make you profit from gambling. Gamble is entirely based on luck, learning how to control your emotions only helps you make good responsible decisions so you don't fall into addiction or make irresponsible decisions because of frustration. That is why we don't have anyone who can boldly say he's a gambling expert the loses alway comes around and if you try chasing profit at all cost you'll only end up losing more than you can imagine, its a simple rule that's constant in gambling. Most people lack the ability to manage their financial risks and know how much should be spent on gamble.
Just like what we have with trading, gambling is a game of luck and for you to win, you have to be highly lucky and to be smart to take the right action this is because managing your available resources to be able to meet up with your gambling demands and not overstepping your set limits is something that will help you as a gambler to remain at a safer state.
Sometimes these mistakes some gamblers make result in addictions and indebtedness in some cases which need to be carefully treated.
gambling addictions and even mistakes are not easy issues to deal with, each case has it own details and people should examine it carefully before making a decision
knowing your limits and learning about your common reactions is usually an important thing to keep in mind and to observe if you want to suceed longterm