Arming oneself is a feel-good consumer product in an increasingly uncertain political environment in the US.

Effective? No, as you have already pointed out, the State is always armed better than you.

Counter-productive? Yes, by directly funding the all right-wing arms industry, their army of government lobbyists, and putting more guns on the streets that increases the already-high risk of random gun violence.

Having a firearm in your home increases the risk of it being used against your family.

Feel good? Yes. A consumerist instant gratification to the need for security. Consumers are what Americans are trained to be.