Do families get to go anywhere for more than a few hours? How do you bring all their stuff along like clothes, toothbrush, etc. Every child needs a minimum of 1l of water all the time, and some snacks in case they get hungry. And toys. And change of clothes in case they spill the 1l of water on themselves in the winter.
What happens when both parents have 20kg+ bags and one of your children decides to run away, say into traffic?
Judging by the replies to my original comment, not many people on HN have children or have any idea what it involves.