It's more of a cost to society. Once they lose all their money, what happens? They either turn to crime or rely on social services. In both cases society pays more than the would have otherwise.

A ton of people I know have a cousin or a brother in law that have been slowing draining bank accounts on DraftKings for years. Their spouses and children only find out once there is no money to pay bills. In one case a set of retired parents went back to work parttime to help support their grandchildren after their adult son wasted all their money and then lost their house.

No its not the gore-splattered event of a drunk driving car accident, but it still tears apart families.

It harms those who are dependent on your income, such as your family.

Not everyone has people dependent on their income. Is it without harm? No, but it's not the same as putting random innocent people at risk. Even with that, the harm you're talking about is not direct - they lose income, but with drunk driving and smoking people directly die.

That's reasonable. But it's also reasonable to ask what the government's responsibility is in protecting those people.

As a society we've already decided it is the job of the government to at least care for children and other adults who aren't capable through both direct aid and forcing adults to take care of them (child support being the most obvious example).

I'd say it falls into a similar realm -- protecting those who can't protect themselves.