Charity would be enough if people put as much time, energy, and resources into providing it as they do in demanding the government do that for them.
A traffic light IS social contract benefiting all and, because it does not discriminate in who it benefits, is a legitimate function of good government.
But forcing Citizen A to fork over his hard earned money to Citizen B who did not earn it or do anything to deserve it cannot be justified under any definition of human rights. Human rights respects each person deciding for himself how he will enjoy and use the fruit of his own labor.
Citizen B may be in dire circumstances and I have no problem with social contract providing help for him. I have no problem with government making it easier to provide help for him. But once you establish a welfare state, you promote more and more need for welfare.
“I am for doing good to the poor, but...I think the best way of doing good to the poor, is not making them easy in poverty, but leading or driving them out of it. (In his travels). . .I observed...that the more public provisions were made for the poor, the less they provided for themselves, and of course became poorer. And, on the contrary, the less was done for them, the more they did for themselves, and became richer.”
― Benjamin Franklin
“You cannot legislate the poor into freedom by legislating the wealthy out of freedom. What one person receives without working for, another person must work for without receiving. The government cannot give to anybody anything that the government does not first take from somebody else. When half of the people get the idea that they do not have to work because the other half is going to take care of them, and when the other half gets the idea that it does no good to work because somebody else is going to get what they work for, that my dear friend, is about the end of any nation. You cannot multiply wealth by dividing it.”
― Adrian Rogers