Sins and benefits for the people


What is the good in gambling, since God say in the Quran that there is good in intoxicants and also in gambling, but the bad outweighs the good?


Indeed, intoxicants, as well as gambling, hold benefits for the people as well as incurring sins:

They ask you about intoxicants and gambling, say, "In them are gross sins and benefits for the people, and their sinfulness is greater than their benefits."

With regards to gambling any trade transaction that involves buying and selling, or setting up a new business for example, contains an element of risk. The risk we take is a gamble.
God did not prohibit trade (2:275), albeit they include a gamble. God allows us to take such risks/gambles, and God says that these can be beneficial for us.
A trader may one day buy jeans from the far east with the purpose of selling them at a profit in Europe or America. This transaction was a gamble/risk because when he bought the jeans he was hopeful of a good return, but still, he did not know with certainty whether he will make profit or loss.
When he comes to sell the jeans, he may make a good profit on his money (thus the gamble was of benefit). However, he may lose money, for any number of reasons.
For example, the trader may find that someone else is already selling the same jeans cheaper than what he paid for them, thus his stock is of little value, and he may need to sell it at a loss.
Since trade is allowed by God, thus this trade, with all risks included, is allowed by God.
This is totally different from people who are compulsive gamblers and it consumes all their lives, causing them untold problems in their lives, animosity with others, and also distracts them from the remembrance of God:

The devil only wants to provoke animosity and hatred between you through intoxicants and gambling, and to repel you from the remembrance of God and from the Salat. So will you thus refrain? 5:91