I notice in alot of mid or post-apocalypse series, almost no thought is given to the children population being 0%-2%. Years into it you'd think people would re-establish and make enough children for mankind to survive, but no. Strong wammen keep taking high-risk positions, even if pregnant.

Now you can argue "child actors is bad long term" for why background characters also have 0, rarely 1 or 2 children in their care.

But this is also the norm in cartoon/Anime. And extends to genres like medieval fantasy where it seems every town or city must be headed to demographic collapse given the age pyramid.

Strong whammen fighters with no kids, the plebs with 0 - 2 kids. In a setting with sustained, very high mortality, you'd expect families of 3 - 5 kids being the norm. Especially in rural areas. Nope. 0 - 2 kids.