That is why a gambler is always advised to have the ability to stop at the right time, the first reason is because even though you have the skills but still if luck is not with you then defeat will also occur, and besides that as you said that when a gambler continues to play after winning then it is the same as you directing yourself to lose the amount of money that has previously been won (although I know the chance of getting another win is still possible), but in the end, isn't prevention always the best action? and in that situation you have managed to achieve a number of wins and isn't that what you want? Obviously, and that is why greed is always a prohibited action, none other than to avoid the possibility of losing the amount that has previously been won and also none other than to avoid yourself from significant regret. Utilizing the winnings for other potentially profitable things is also a good idea.
We must have control over ourselves so we can stop anytime especially when we wins so much money. We don't have to risks our win money to keep playing gambling and expecting to wins more money. We don't have a guarantee to wins many times in the next rounds so we must know when we must stop gambling.
Playing gambling and hopes we can wins more and more can makes us forget that gambling is not a place to make money. We will lose our money with our win money so we will not get anything from gambling and only lose the money.
That is why we must control ourselves from greediness because that is very dangerous if we can not do that. Many people already lose much money from gambling so we must be careful especially after winning some money. No need to chase the next wins since we can win again in the next day and it is enough for our wins today.