The Torah describes the miracles and the overall bliss and abundance of life in the desert - free unlimited food, clothes, footwear, no illnesses incl. infant mortality, etc.
On the other hand, no seeming permission for contraceptives, and overall desire to grow the Jewish population further. I personally, see no reason not to take advantage of the situation to procreate to the maximum possible.
Why didn't Dor Hamidbar have, say, 20 kids per family?