having many kids is actually not very expensive at all and each one gets cheaper and cheaper. And if you believe there is no benefit, then you are very short sighted, because children are who is going to take care of you when you are old.
Well as to your first part you’re looking out at as a matter of economies of scale. So the more kids you have the lower the unit cost is. Kind of like manufacturing millions of cookies in a factory versus making a dozen at home. The unit cost becomes cheaper when you make millions. Got it so it’s an economic decision then. As to your second part who’s going to take care of you when you’re old? So you had children as an insurance policy or Hedge for failing health in old age. Got it.
What self respecting person wants there kids to grow up like weeds? Gonna kick your weed out at 18 with no money, no education ?