Then $1.6k/kid gets subtracted due to the Child Tax Credit, for a net -$700 in taxes paid.
Keep in mind the cost of living in the USA is higher than many other countries. 60k for a family of four is doable in most places, but it is not a life of luxury.
edit: the family will also end up paying 7.65%/$4.6k in a separate tax for a mandatory retirement scheme (FICA)