A bunch of things are at play here.

This is actually a good thing for personal autonomy. Instead of accidentally having kids you can't afford, due to modern science, it's completely optional.

The article alludes to this, but the government previously promoted smaller families. Just a few generation ago the birthrate was considered too high. Realistically to have a growing population you probably want to have around an average of 3 children per couple.

This is economically impossible for most people though. No one has a stable job anymore. We're all temps and gig workers.

If you just do it anyway, and find it's a struggle... Society blames you and calls you careless.

The path of least resistance is to just skip having a family.