Actually everything has its own risks, including in gambling. Everyone knows that gambling never guarantees the win, it even spends a lot our money. If we have no control for our emotion, we may be influenced to spend all the money to chase the wins. Or we may be triggered to gamble as much as possible to recover the losses. This is totally wrong way in gambling, this will lead into an excessive gambling. The only way is to limit control our emotion by limiting the funds and the time to play gambling games. So, it is true that controlling emotion is very important in gambling.
Controlling one's emotions is what a gambler should even test and work on before embarking on gambling. After that, you move to training yourself to always keep to the amount you have set as a limit for gambling and the time frame to spend on each day you decide to gamble, because if someone doesn't have that control in them, even setting up rules and limits to keep them on track, they will always easily break that limit themselves; it won't stand for long, especially when they get emotionally attached to the game, either due to losing or winning.
Setting the amount to be allocated can be done by everyone, but maintaining it is the point of difficulty, I am sure everyone does not want to experience big losses in gambling but consciously or unconsciously sometimes they forget the limits that they should obey until what they do is gamble beyond reasonable limits. And with someone who does not have self-control, this allows them to be easily provoked by their emotions, it is not strange if they say gambling is a scam because they cannot accept the defeat that occurs. Gambling is basically a means of entertainment in the form of a game, it's just that this is the seriousness of some people who do it, of course, those who have the goal of being able to get profit from gambling continuously, this is ridiculous because there is no victory that can be obtained continuously.