I also believe that greed is the main reason for major losses in gambling. The unwillingness to let go of something you’ve already imagined as yours leads to reckless actions and risks you're not prepared for. And by the time clarity comes it’s often too late. That’s why it’s important to have something or someone who can stop you in time, remind you of your limits, and bring you back to reality before the thrill of gambling completely clouds your judgment.
Greed and for those who wouldn't let go of their losses, having greed of making large profits is a reason why gamblers lose a lot but there are some also who gamble without greed but hence don't like losing all deposits to the casino, this set as well often hits greater losses because what can't be changed is that the casino is meant to do better than gamblers and only way out is for gamblers not to chase what was lost.
Nowadays, casinos are able to understand the types of gamblers and their mentality. Because of this, they can treat gamblers according to their gambling style. They are able to understand well which gamblers are greedy and how long they gamble and how they behave after winning or losing. If a gambler does not control himself, then he will lose very soon. Because greed will work in him. He will try his best to recover his loss, but at some point he will lose everything. Therefore, no matter what the loss is, there must be control.